Hi thank you for the prompt response.
I would like to append all those BN parameters to form a list for separate training with a different learning rate.
Is my implementation reasonable?
bn_paras = list()
for layer in resnet.modules():
    if isinstance(layer,torch.nn.modules.batchnorm.BatchNorm2d): 
        bn_paras.append(layer.parameters())
print(len(bn_paras))