Question: I have installed magento2.1 in local pc. After I created one custom theme then, I Go to change my custom theme via admin **Store -> Configuration -> General -> Design** But Here Theme Selection option is not there , Is magento 2.1 Bug? 

Reference: 

[![enter image description here](https://i.stack.imgur.com/a9Bs5.png)](https://i.stack.imgur.com/a9Bs5.png)

Answer: 
There is nothing wrong with your installation. I believe they moved it to the design tab in a newer version.

In my 2.1 version also it shows same. <https://drive.google.com/file/d/0B1aJL9nhfbfFZ3JKeWszcVczSjQ/view?usp=drivesdk>

It seems the theme configuration was moved.

It can be found in main administration menu:

Content -> Design -> Configuration Click on scope you are interested in(probably the first one) and change 'Applied theme'.
No That is no bug

replace 2.1 in

Please go to content-> Configuration -> edit