By applying rotated empirical orthogonal function(REOF) analysis to precipitation in rainy season(April-September) from 1951 to 2003 at 114 selected stations over eastern China,defined by the large contours of the five REOF modes,5 active centers are identified:the southern part of Northeast China,the Hetao region,the Yangtze and Huaihe river basins,the middle and lower Yangtze River valley and South China.Morlet wavelet analysis indicates that there have different oscillation periods in addition to the 7～8-year period in each region.Long-term trends show that the subareas basically presented tow-waves in the 53-year,and the southern part of Northeast China,the Hetao region,the Yangtze and Huaihe river basins all had a sudden change of precipitation in rainy season around the late 1960’s with a evident decreasing,but the middle and lower Yangtze River valley and South China had a sudden change in the early 1990’s with a weak rising.