I saw tutorial in youtube that in POSE MODE , all of bones had box around them and when the bone was moving, parent bones also moved.how to do this?
you can change the appearance of your bones to boxes called b-bones.
with Ctrl Alt S you can change the thickness of the b-bone in edit mode. And If you want to make your bone see trough, go to your object properties and under Display, change the maximum draw type to wire
And Bones can affect their parents with the bone constraint: Inverse Kinematic.