Citizens of Japan, Singapore and Mongolia can receive a 15 day visa on arrival. All others need to have a visa before boarding a plane to China. Do not try to fly to China without a visa as they will not let you in. The only exception is a transit visa which you can get at some Chinese airports on arrival, however you need an onwards flight booked to another country. Depending on the airport, Chinese transit visas are issued for different durations, though never for more than three days, so this is not suitable for a Chinese course in Beijing, Shanghai, Chinese immersion or gap year program.