I want to create Custom UIButton with rectangular shape. for this I am using rectangular view as a Background for UIButton and making UIbuttons background colour as clearcolor.
You should set type of your UIButton to Custom, not Rounded Rect (if you are creating button via IB).
UIButton
Custom
Rounded Rect
If you are creating UIButton programmatically then you this code:
UIButton *but = [UIButton buttonWithType:UIButtonTypeCustom];
And after that you can make your own customizations.