I have never seen suspenders for sale in China.  I suppose, if you have pictures, you can have some made in the fabric market in Haiyin Square.

I brought mine from the states, and both students and colleagues stare at me when I take off my coat and they see the suspenders.  Some ask me why do I dress like an "old man" while others think it is cool.
I just like the "retro look" and have enjoyed it since my 20's.

Make some

http://www.autostraddle.com/this-is-a-holdup-make-your-own-suspenders-51...

http://manmadediy.com/chris/posts/190-how-to-make-your-own-suspenders

http://www.ehow.com/how_5541683_make-pants-suspenders.html

Taobao has everything. I don't know the chinese name for them

taobao  男式背带

Try H&M.