The interdecadal variability of precipitation in eastern China is studied based on data from 66 meteorological stations for the period 1880-2010.Combined with the summer Pacific Decadal Oscillation (PDO) during 1900-2010 and NCEP/NCAR data for the period 1961-2010,summer precipitation in eastern China is analyzed corresponding to the different phases of the PDO,and the possible underlying physical mechanism is discussed.In order to resolve the spatial distribution differences,empirical orthogonal function (EOF) analysis is carried out on the summer precipitation in the near 130-year period.Conventional synthesis analysis,the t-test of statistical significance,and sliding correlation analysis are also used.Decadal features are obtained using Fourier filtering,which filtered out less than 10 years.The work presented in this paper is useful in improving our understanding of the decadal characteristics of summer precipitation in eastern China,especially in the context of promoting the forecasting ability of summer precipitation.The results show that the interdecadal variability of precipitation in eastern China is significant,with obvious differences in North China,the Jianghuai region,and South China.Three change-points occur in North China (in the early 1920s,1940s and early 1970s),four in the Jianghuai region (in the early 1920s,1940,late 1950s and 1970s),and three in South China (in the late 1900s,1940s and early 1970s).A dipole (negative-positive or positive-negative) and tripole (negative-positive-negative or positive-negative-positive) distribution are the two main modes of summer precipitation in eastern China,as determined by EOF analysis.In 1929-1944 (positive PDO),summer rainfall in eastern China presents a negative-positive dipole distribution,which indicates the main rain belt to be located in South China,with the negative anomaly in the Jianghuai basin.During 1945-1977 (negative PDO),the meridional distribution of summer rainfall in eastern China is characterized by a positive-negative-positive tripole pattern,with the main rain belt in North China and South China.In another positive phase of the PDO (1978-2005),the spatial structure of precipitation follows a negative-positive dipole distribution-opposite to that of the previous positive PDO phase-with the main rain belt in eastern China located in the Jianghuai region and the negative anomaly in North China and South China.We also find through sliding correlation analysis that summer precipitation in different areas of eastern China show response characteristics according to the different phases of the PDO.It is apparent that the location of the main rain belt is not only affected by the phase of the PDO,but also by the main circulation system (e.g.the western Pacific subtropical high,East Asia teleconnection and East Asia blocking high).The interdecadal components of the 500-hPa height field and Pacific SST in the summer,via canonical correlation analysis,indicates that the positive phase of the PDO can trigger a negative wave train of the Pacific-Japan teleconnection.This negative teleconnection wave train can lead to more precipitation over the middle and lower reaches of the Yangtze river,less precipitation over North China,and vice versa.