【摘要】One of the main characteristics for business cycle is the co\|movements of many broadly defined economic aggregates. Which factor mainly causes the business cycle? Western business cycle theories have different opinions on this issue. This papers uses Unit Root Test and Granger Causality Test to do positive analysis on the causality relationship of the economic aggregates of Chinese business cycle and exploits the reasons and the fluctuation mechanism of Chinese business cycle from 1977 to 1999.