Entry requirements vary by school with the most prestigious schools having the strictest requirements. In general the following principles apply:
Best is to contact the international office of the university in which you are interested well ahead of time to find out the exact procedures applying to foreigners.
Many schools require a combination of written tests and an interview, though trends are shifting toward interview, transcript and recommendation-based admission.
Typically these tests are held between February and May.
Chinese applicants meantime, given their numbers, face more competitive entry than foreign students. Life is harder for foreigners however, once classes begin.
For courses taught in Chinese a score of 8 or 9 in the intermediate HSK exam, or Hanyu Shuiping Kaoshi, is required. See below for further details.
The GMAT exam is required for entry into higher end business schools, at least those in which instruction is in English. http://www.mba.com/mba/thegmat