Since IFATC is located in China today I found it a wonderful time to discuss the difference in flight levels in Chinese airspace. If you have ever gone on flightradar24.com and looked at flights over China you may have noticed that the altitudes the aircraft are flying at all are 100ft higher than the other flight levels operated in the world. But why is that? Well this comes down to the metric problem or China implementing their RVSM scheme (Reduced Vertical Separation Minimum). China operates its flights using the metric system for assigning flight levels due to the requirement by the Chinese military. This means that altitudes are assigned in Meters and to keep a long story short, that means that the altitudes dont directly translate to the the standard operating flight levels since the rest of the world has flight levels standardized with the imperial foot. Without making it too complex when you are operating in Chinese airspace be sure to put an extra 100ft on your altitude and upon leaving their airspace reduce your altitude by 100ft.
For more info look at the FAA document on the flight separation in China