China is not really Communist.
There is nothing wrong with being communist, and you can call us that if you wish, it does not matter. If we are trying to use the "correct words" though, here is the definition of Communism:
Communism is the abolishment of private property, a system where everything is collectively owned by the "state".
This is clearly not the case in China today, and has not been the case since the market reforms of 1978. Today, China participates openly in the international markets... and in fact has the second largest "market economy" on Earth.
But as I said, you can use any word you want. The most correct description would probably be a
"one-party socialist state".