Based on the 1960—2011 monthly precipitation data of 65 meteorological stations in Shanxi province, NCEP/NCAR reanalysis data and NOAA monthly sea surface temperature(SST) data, the harmonic analysis, SVD method, Monte Carlo statistical test, EOF method and composite analysis method are used to study the interdecadal variation of summer precipitation in Shanxi and its relationship with the general circulation and the SST abnormalities in Indian Ocean. Results show that summer precipitation of Shanxi has a decreasing trend in the recent 52 years, and it presents a significant interdecadal variation characteristic that more precipitation happened from the early 1960's to early 1980's while less precipitation occurred from the mid-1980's to 2011. The spatial distributions of summer precipitation in Shanxi include consistent type (more or less precipitation in entire Shanxi) and north-south type(more precipitation in north(south), less precipitation in south(north)). There has significant negative correlation between summer rainfall of Shanxi and SST of key area in India ocean, when the SST is anomaly higher in last autumn and winter, this summer precipitation of Shanxi decreases, and vice versa. Before 1982, the SST was lower, the northeast cold vortex and the trough at 500 hPa over Ural Mountains and northern Qinghai-Tibet Plateau were deeper and more active, and the west Pacific subtropical high was weaker and locates more easterly, and the synchronous low-latitude westerly winds and the mid-latitude 850 hPa-southwest wind unusually strengthened and the vortex over Lake Baikal was active. After 1982, the SST was higher, from Lake Baikal to northern Qinghai-Tibet plateau are controlled by high pressure, and the intensity of the 500 hPa western Pacific subtropical high was stronger and located more western. The 850 hPa mid-latitude southwest wind was unusually weaker.% 利用山西省65个气象站1960—2011年逐月降水资料、NCEP/NCAR再分析资料和NOAA月平均海表温度资料等,应用谐波分析、EOF、SVD、Monte Carlo统计检验和合成分析等方法,探讨了山西夏季降水年代际变化特征,以及其与大气环流场、印度洋海温场异常的关系。结果表明,近52 a来,山西夏季降水总体呈现减少趋势,并有明显年代际变化特征：20世纪60年代初至80年代前期是降水偏多期,80年代中期至2011年则是降水偏少期,空间分布主要包括全省一致偏多(少)型和南多北少(南少北多)型。同时,山西夏季降水与印度洋关键区海温变化具有明显的负相关,当上年秋季、上年冬季、当年春季和当年夏季关键区海温异常偏高时,当年夏季山西降水呈现减少趋势,反之亦然。在1982年之前,关键区海温偏低,山西夏季降水偏多,同期500 hPa高度层上的乌拉尔山、青藏高原北部高空槽和东北冷涡发展深厚,活动频繁,西太平洋副热带高压强度偏弱、位置偏东,850 hPa高度层上的印度季风低纬度偏西风和中纬度西南风异常强盛,贝加尔湖南侧低涡活跃；1982年之后,关键区海温偏高,山西夏季降水随之减少,同期500 hPa高度层上的贝加尔湖至青藏高原北部地区受高压控制,西太平洋副热带高压强度偏强、位置偏西,850 hPa高度层上的印度季风中纬度西南风异常偏弱。
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