I found wrapping sliced part of parameter by Variable doesn’t update original parameter. I noticed it because loss function doesn’t change.
tensor(1.00000e-03 *
       5.0263)
tensor(1.00000e-03 *
       5.0263)
tensor(1.00000e-03 *
       5.0263)
tensor(1.00000e-03 *
       5.0263)
.
.
.

In order to caliculate my loss function, I have to use whole dimention of parameter.