The US$1 coin didn't go over very well when it was introduced and these days you'll very rarely come across one. In China, there is a RMB1 coin as well as a paper bill, but interestingly enough in China's 2 major cities, things work very differently.
In Shanghai, you almost always will receive RMB1 coins from taxi drivers, shops, and restaurants, while in Beijing, you can go a month and not come across a single RMB1 coin, instead you almost always see bills here.
Why is this? The only possible hypothesis we have as to why RMB1 coins have such high circulation in Shanghai is because of the subway machines, the majority of which accept coins only. Any other guesses? It will be interesting to see if coins start popping up more in Beijing after the new ticketing machines open up in the subway.