Keywords: 
• 年代际 /
• 降水 /
• 北太平洋年代际涛动 /
• 东亚夏季风

Abstract: Considering the abnormal precipitation in north-west and drougtin south China during the summer of 2012, we have analyzed the decadal precipitation distribution and the chief probably-influencing factors in recent 50 years, in order to make a discussion of the possibility of decadal change of summer precipitation in East China since the summer of 2012. Research results show that the north Pacific decadal oscillation (PDO) is in cold phase, and the north cold air active and the west Pacific subtropical high (WPSH) are both in weak phase during the summer of 1961–1978. This situation is beneficial to the strong east Asia summer monsoon (EASM) and the north expansion of the low latitude water vapor, causing the summer precipitation in northern China more than normal in this decadal. While the situation is in quite opposite way during 1979–1992 (which causes the decadal change of summer precipitation in east China) that the precipitation is less than normal in northern China during the late period. Meanwhile, since in the late 2010 PDO changed from the warm phase to cold phase, the sea surface temperature was warmer in north Pacific and colder in west Pacific than normal, while the west Pacific subtropical high and the north region cold air active both changed from strong phase to weak phase, and the EASM became stronger, quite similar to that in 1961–1978. All of the cases showed that there might be once more a decadal change of summer precipitation in East China since the summer of 2012. Furthermore, the yearly variation of indices of PDO, EASM, WPSH and Baikal Height (BH) showed that the abnormal precipitation distribution and the chief influencing factors are not only the yearly variables but also the probable signal of decadal change in the following years.