The Chinese Proficiency Test (Hànyǔ Shuǐpíng Kǎoshì, HSK) is China's national standardized test of Chinese as a foreign language.

HSK has three levels: HSK Basic (beginning level), HSK Elementary-Intermediate (elementary to intermediate level), and HSK Advanced (advanced level).

HSK is held regularly in China and in other countries each year.  The timetable in mainland China is as follows:

　HSK（Basic）：                              April and December
　HSK（Elementary-Intermediate）： April, June and December
　HSK（Advanced）：                       April and October

HSK is scored on a scale of 1 to 11. The elementary test covers levels
1-3, the intermediate test covers levels 3-8, and the advanced test
covers levels 9-11. HSK certificates are issued to those who meet required scores.

One of the primary and most common uses of the test
is for international students who wish to enroll in a Chinese
university as a full time student to demonstrate the required Chinese
proficiency. Generally, a score of six is necessary to enroll in a
Chinese university.

In
addition, test takers with outstanding results have the chance to win a
scholarship for a short-term language study in China.

For more details, you can go to HSK Official Site
For English version of HSK official site, you can go to HSK English Site.