to verify whether is geniue Kansu YSK year three soviet chop

[Ah Heng]

To verify whether is genuine. the year 1990 world catalogue have this coin, but lately, people say is fake. 

[JKK]

First thing I would do is hold it up to a magnet. Most of the Chinese fakes I've seen from the late Empire and early Republic jump to a magnet. If it doesn't, then weigh it and compare it to the reference of what the coin is supposed to weigh. If it doesn't weigh out correctly, it's definitely a counterfeit.