diff --git a/README.md b/README.md
index c5c4eb6..cafebc1 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,22 @@
-# External-Attention-pytorch
+- [Attention Series](#attention-series)
+    - [1. External Attention Usage](#1-external-attention-usage)
+
+    - [2. Self Attention Usage](#2-self-attention-usage)
+
+    - [3. Simplified Self Attention Usage](#3-simplified-self-attention-usage)
+
+    - [4. Squeeze-and-Excitation Attention Usage](#4-squeeze-and-excitation-attention-usage)
+
+    - [5. SK Attention Usage](#5-sk-attention-usage)
+
+    - [6. CBAM Attention Usage](#6-cbam-attention-usage)
+
+    - [7. BAM Attention Usage](#7-bam-attention-usage)
+
+- [MLP Series](#mlp-series)
+    - [1. RepMLP Usage](#1-RepMLP-Usage)
+
+# Attention Series
 
 Pytorch implementation of ["Beyond Self-attention: External Attention using Two Linear Layers for Visual Tasks"](https://arxiv.org/abs/2105.02358)
 
@@ -160,3 +178,58 @@ output=bam(input)
 print(output.shape)
 
 ```
+
+
+
+
+
+***
+
+# MLP Series
+
+Pytorch implementation of ["RepMLP: Re-parameterizing Convolutions into Fully-connected Layers for Image Recognition"](https://arxiv.org/pdf/2105.01883v1.pdf)
+
+
+### 1. RepMLP Usage
+#### 1.1. Paper
+["RepMLP: Re-parameterizing Convolutions into Fully-connected Layers for Image Recognition"](https://arxiv.org/pdf/2105.01883v1.pdf)
+
+#### 1.2. Overview
+![](./img/repmlp.png)
+
+#### 1.3. Code
+```python
+from mlp.repmlp import RepMLP
+import torch
+from torch import nn
+
+N=4 #batch size
+C=512 #input dim
+O=1024 #output dim
+H=14 #image height
+W=14 #image width
+h=7 #patch height
+w=7 #patch width
+fc1_fc2_reduction=1 #reduction ratio
+fc3_groups=8 # groups
+repconv_kernels=[1,3,5,7] #kernel list
+repmlp=RepMLP(C,O,H,W,h,w,fc1_fc2_reduction,fc3_groups,repconv_kernels=repconv_kernels)
+x=torch.randn(N,C,H,W)
+repmlp.eval()
+for module in repmlp.modules():
+    if isinstance(module, nn.BatchNorm2d) or isinstance(module, nn.BatchNorm1d):
+        nn.init.uniform_(module.running_mean, 0, 0.1)
+        nn.init.uniform_(module.running_var, 0, 0.1)
+        nn.init.uniform_(module.weight, 0, 0.1)
+        nn.init.uniform_(module.bias, 0, 0.1)
+
+#training result
+out=repmlp(x)
+
+
+#inference result
+repmlp.switch_to_deploy()
+deployout = repmlp(x)
+
+print(((deployout-out)**2).sum())
+```
diff --git a/img/repmlp.png b/img/repmlp.png
new file mode 100644
index 0000000..3f94493
Binary files /dev/null and b/img/repmlp.png differ
diff --git a/main.py b/main.py
index 38600c1..28e32d2 100644
--- a/main.py
+++ b/main.py
@@ -1,7 +1,33 @@
-from attention.BAM import BAMBlock
+from mlp.repmlp import RepMLP
 import torch
+from torch import nn
 
-input=torch.randn(50,512,7,7)
-bam = BAMBlock(channel=512,reduction=16,dia_val=2)
-output=bam(input)
-print(output.shape)
\ No newline at end of file
+N=4 #batch size
+C=512 #input dim
+O=1024 #output dim
+H=14 #image height
+W=14 #image width
+h=7 #patch height
+w=7 #patch width
+fc1_fc2_reduction=1 #reduction ratio
+fc3_groups=8 # groups
+repconv_kernels=[1,3,5,7] #kernel list
+repmlp=RepMLP(C,O,H,W,h,w,fc1_fc2_reduction,fc3_groups,repconv_kernels=repconv_kernels)
+x=torch.randn(N,C,H,W)
+repmlp.eval()
+for module in repmlp.modules():
+    if isinstance(module, nn.BatchNorm2d) or isinstance(module, nn.BatchNorm1d):
+        nn.init.uniform_(module.running_mean, 0, 0.1)
+        nn.init.uniform_(module.running_var, 0, 0.1)
+        nn.init.uniform_(module.weight, 0, 0.1)
+        nn.init.uniform_(module.bias, 0, 0.1)
+
+#training result
+out=repmlp(x)
+
+
+#inference result
+repmlp.switch_to_deploy()
+deployout = repmlp(x)
+
+print(((deployout-out)**2).sum())
\ No newline at end of file
diff --git a/mlp/repmlp.py b/mlp/repmlp.py
new file mode 100644
index 0000000..8c9e235
--- /dev/null
+++ b/mlp/repmlp.py
@@ -0,0 +1,232 @@
+import torch
+from torch import nn
+from collections import OrderedDict
+from torch.nn import functional as F
+import numpy as np
+from numpy import random
+
+
+def setup_seed(seed):
+     torch.manual_seed(seed)
+     torch.cuda.manual_seed_all(seed)
+     np.random.seed(seed)
+     random.seed(seed)
+     torch.backends.cudnn.deterministic = True
+
+class RepMLP(nn.Module):
+    def __init__(self,C,O,H,W,h,w,fc1_fc2_reduction=1,fc3_groups=8,repconv_kernels=None,deploy=False):
+        super().__init__()
+        self.C=C
+        self.O=O
+        self.H=H
+        self.W=W
+        self.h=h
+        self.w=w
+        self.fc1_fc2_reduction=fc1_fc2_reduction
+        self.repconv_kernels=repconv_kernels
+        self.h_part=H//h
+        self.w_part=W//w
+        self.deploy=deploy
+        self.fc3_groups=fc3_groups
+
+        # make sure H,W can divided by h,w respectively
+        assert H%h==0
+        assert W%w==0
+
+        self.is_global_perceptron= (H!=h) or (W!=w)
+        ### global perceptron
+        if(self.is_global_perceptron):
+            if(not self.deploy):
+                self.avg=nn.Sequential(OrderedDict([
+                    ('avg',nn.AvgPool2d(kernel_size=(self.h,self.w))),
+                    ('bn',nn.BatchNorm2d(num_features=C))
+                ])
+                )
+            else:
+                self.avg=nn.AvgPool2d(kernel_size=(self.h,self.w))
+            hidden_dim=self.C//self.fc1_fc2_reduction
+            self.fc1_fc2=nn.Sequential(OrderedDict([
+                ('fc1',nn.Linear(C*self.h_part*self.w_part,hidden_dim)),
+                ('relu',nn.ReLU()),
+                ('fc2',nn.Linear(hidden_dim,C*self.h_part*self.w_part))
+            ])
+            )
+
+        self.fc3=nn.Conv2d(self.C*self.h*self.w,self.O*self.h*self.w,kernel_size=1,groups=fc3_groups,bias=self.deploy)
+        self.fc3_bn=nn.Identity() if self.deploy else nn.BatchNorm2d(self.O*self.h*self.w)
+        
+        if not self.deploy and self.repconv_kernels is not None:
+            for k in self.repconv_kernels:
+                repconv=nn.Sequential(OrderedDict([
+                    ('conv',nn.Conv2d(self.C,self.O,kernel_size=k,padding=(k-1)//2, groups=fc3_groups,bias=False)),
+                    ('bn',nn.BatchNorm2d(self.O))
+                ])
+
+                )
+                self.__setattr__('repconv{}'.format(k),repconv)
+                
+
+    def switch_to_deploy(self):
+        self.deploy=True
+        fc1_weight,fc1_bias,fc3_weight,fc3_bias=self.get_equivalent_fc1_fc3_params()
+        #del conv
+        if(self.repconv_kernels is not None):
+            for k in self.repconv_kernels:
+                self.__delattr__('repconv{}'.format(k))
+        #del fc3,bn
+        self.__delattr__('fc3')
+        self.__delattr__('fc3_bn')
+        self.fc3 = nn.Conv2d(self.C * self.h * self.w, self.O * self.h * self.w, 1, 1, 0, bias=True, groups=self.fc3_groups)
+        self.fc3_bn = nn.Identity()
+        #   Remove the BN after AVG
+        if self.is_global_perceptron:
+            self.__delattr__('avg')
+            self.avg = nn.AvgPool2d(kernel_size=(self.h, self.w))
+        #   Set values
+        if fc1_weight is not None:
+            self.fc1_fc2.fc1.weight.data = fc1_weight
+            self.fc1_fc2.fc1.bias.data = fc1_bias
+        self.fc3.weight.data = fc3_weight
+        self.fc3.bias.data = fc3_bias
+
+
+
+
+    def get_equivalent_fc1_fc3_params(self):
+        #training fc3+bn weight
+        fc_weight,fc_bias=self._fuse_bn(self.fc3,self.fc3_bn)
+        #training conv weight
+        if(self.repconv_kernels is not None):
+            max_kernel=max(self.repconv_kernels)
+            max_branch=self.__getattr__('repconv{}'.format(max_kernel))
+            conv_weight,conv_bias=self._fuse_bn(max_branch.conv,max_branch.bn)
+            for k in self.repconv_kernels:
+                if(k!=max_kernel):
+                    tmp_branch=self.__getattr__('repconv{}'.format(k))
+                    tmp_weight,tmp_bias=self._fuse_bn(tmp_branch.conv,tmp_branch.bn)
+                    tmp_weight=F.pad(tmp_weight,[(max_kernel-k)//2]*4)
+                    conv_weight+=tmp_weight
+                    conv_bias+=tmp_bias
+            repconv_weight,repconv_bias=self._conv_to_fc(conv_weight,conv_bias)
+            final_fc3_weight=fc_weight+repconv_weight.reshape_as(fc_weight)
+            final_fc3_bias=fc_bias+repconv_bias
+        else:
+            final_fc3_weight=fc_weight
+            final_fc3_bias=fc_bias
+
+        #fc1
+        if(self.is_global_perceptron):
+            #remove BN after avg
+            avgbn = self.avg.bn
+            std = (avgbn.running_var + avgbn.eps).sqrt()
+            scale = avgbn.weight / std
+            avgbias = avgbn.bias - avgbn.running_mean * scale
+            fc1 = self.fc1_fc2.fc1
+            replicate_times = fc1.in_features // len(avgbias)
+            replicated_avgbias = avgbias.repeat_interleave(replicate_times).view(-1, 1)
+            bias_diff = fc1.weight.matmul(replicated_avgbias).squeeze()
+            final_fc1_bias = fc1.bias + bias_diff
+            final_fc1_weight = fc1.weight * scale.repeat_interleave(replicate_times).view(1, -1)
+
+        else:
+            final_fc1_weight=None
+            final_fc1_bias=None
+        
+        return final_fc1_weight,final_fc1_bias,final_fc3_weight,final_fc3_bias
+
+
+
+
+    # def _conv_to_fc(self,weight,bias):
+    #     i_maxtrix=torch.eye(self.C*self.h*self.w//self.fc3_groups).repeat(1,self.fc3_groups).reshape(self.C*self.h*self.w//self.fc3_groups,self.C,self.h,self.w)
+    #     fc_weight=F.conv2d(i_maxtrix,weight=weight,bias=bias,padding=weight.shape[2]//2,groups=self.fc3_groups)
+    #     fc_weight=fc_weight.reshape(self.C*self.h*self.w//self.fc3_groups,-1)
+    #     fc_bias = bias.repeat_interleave(self.h * self.w)
+    #     return fc_weight,fc_bias
+
+
+    def _conv_to_fc(self,conv_kernel, conv_bias):
+        I = torch.eye(self.C * self.h * self.w // self.fc3_groups).repeat(1, self.fc3_groups).reshape(self.C * self.h * self.w // self.fc3_groups, self.C, self.h, self.w).to(conv_kernel.device) 
+        fc_k = F.conv2d(I, conv_kernel, padding=conv_kernel.size(2)//2, groups=self.fc3_groups)
+        fc_k = fc_k.reshape(self.C * self.h * self.w // self.fc3_groups, self.O * self.h * self.w).t()
+        fc_bias = conv_bias.repeat_interleave(self.h * self.w)
+        return fc_k, fc_bias
+
+
+    def _fuse_bn(self, conv_or_fc, bn):
+        std = (bn.running_var + bn.eps).sqrt()
+        t = bn.weight / std
+        if conv_or_fc.weight.ndim == 4:
+            t = t.reshape(-1, 1, 1, 1)
+        else:
+            t = t.reshape(-1, 1)
+        return conv_or_fc.weight * t, bn.bias - bn.running_mean * bn.weight / std
+
+
+    def forward(self,x) :
+        ### global partition
+        if(self.is_global_perceptron):
+            input=x
+            v=self.avg(x) #bs,C,h_part,w_part
+            v=v.reshape(-1,self.C*self.h_part*self.w_part) #bs,C*h_part*w_part
+            v=self.fc1_fc2(v) #bs,C*h_part*w_part
+            v=v.reshape(-1,self.C,self.h_part,1,self.w_part,1) #bs,C,h_part,w_part
+            input=input.reshape(-1,self.C,self.h_part,self.h,self.w_part,self.w) #bs,C,h_part,h,w_part,w
+            input=v+input
+        else:
+            input=x.view(-1,self.C,self.h_part,self.h,self.w_part,self.w) #bs,C,h_part,h,w_part,w
+        partition=input.permute(0,2,4,1,3,5) #bs,h_part,w_part,C,h,w
+
+        ### partition partition
+        fc3_out=partition.reshape(-1,self.C*self.h*self.w,1,1) #bs*h_part*w_part,C*h*w,1,1
+        fc3_out=self.fc3_bn(self.fc3(fc3_out)) #bs*h_part*w_part,O*h*w,1,1
+        fc3_out=fc3_out.reshape(-1,self.h_part,self.w_part,self.O,self.h,self.w) #bs,h_part,w_part,O,h,w
+
+        ### local perceptron
+        if(self.repconv_kernels is not None and not self.deploy):
+            conv_input=partition.reshape(-1,self.C,self.h,self.w) #bs*h_part*w_part,C,h,w
+            conv_out=0
+            for k in self.repconv_kernels:
+                repconv=self.__getattr__('repconv{}'.format(k))
+                conv_out+=repconv(conv_input) ##bs*h_part*w_part,O,h,w
+            conv_out=conv_out.view(-1,self.h_part,self.w_part,self.O,self.h,self.w) #bs,h_part,w_part,O,h,w
+            fc3_out+=conv_out
+        fc3_out=fc3_out.permute(0,3,1,4,2,5)#bs,O,h_part,h,w_part,w
+        fc3_out=fc3_out.reshape(-1,self.C,self.H,self.W) #bs,O,H,W
+
+
+        return fc3_out
+
+
+
+if __name__ == '__main__':
+    setup_seed(20)
+    N=4 #batch size
+    C=512 #input dim
+    O=1024 #output dim
+    H=14 #image height
+    W=14 #image width
+    h=7 #patch height
+    w=7 #patch width
+    fc1_fc2_reduction=1 #reduction ratio
+    fc3_groups=8 # groups
+    repconv_kernels=[1,3,5,7] #kernel list
+    repmlp=RepMLP(C,O,H,W,h,w,fc1_fc2_reduction,fc3_groups,repconv_kernels=repconv_kernels)
+    x=torch.randn(N,C,H,W)
+    repmlp.eval()
+    for module in repmlp.modules():
+        if isinstance(module, nn.BatchNorm2d) or isinstance(module, nn.BatchNorm1d):
+            nn.init.uniform_(module.running_mean, 0, 0.1)
+            nn.init.uniform_(module.running_var, 0, 0.1)
+            nn.init.uniform_(module.weight, 0, 0.1)
+            nn.init.uniform_(module.bias, 0, 0.1)
+
+    #training result
+    out=repmlp(x)
+
+
+    #inference result
+    repmlp.switch_to_deploy()
+    deployout = repmlp(x)
+
+    print(((deployout-out)**2).sum())
\ No newline at end of file