In MyEclipse, F4 shortcut use for finding classes that extends/implements/override current type such as Class/Interface/method.
This shortcut useful for me.
In IntelliJ idea above facility achieve by left green icon of class/interface/method. It means I must click on icon and see list.
My question is : Is there any shortcut in IntelliJ idea similar to MyEclipse that without mouse I find sub class or method?
I think Ctrl-H is what you are looking for.
It will open the inheritance hierarchy in a window.
As yole mentioned, if you want to navigate directly to an implementation of a class or method use Ctrl-Alt-B. It will open the implementation if there is exactly one, or lets you choose one if there are multiple options.