Abstract:Based on the precipitation dataset CN05.1 collected by more than 2 400 observation stations of the China Meteorological Administration, the Extended Reconstructed Sea Surface Temperature Version 4 (ERSST V4) from National Oceanic and Atmospheric Administration Climate Prediction Center (NOAA/CPC), and the 500 hPa geopotential height data and 850 hPa wind and sea level pressure data from the daily reanalysis dataset jointly developed by the National Centers for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR), this paper discusses the characteristics of summer precipitation variation over Jiangsu Province during the last 50 years and its relationship with ENSO in ways of Empirical Orthogonal Function (EOF), the power spectrum, and the correlation analysis. The results show that:(1) There are two typical spatial distribution modes of summer precipitation over Jiangsu Province, namely the first EOF mode and the second EOF mode. The first one shows the spatial distribution pattern of the consistent change of precipitation in the whole Province, while the second mode reflects the reverse change of precipitation in the north and south of Jiangsu Province. (2) The corresponding Principal Components (PCs) of the two EOF modes have different significant periodicities. There is an inter-annual oscillation (a 4/5-year cycle) of the PC1 and an inter-decadal oscillation (a 16-year cycle) of the PC2. (3) The precipitation over the Jiangsu Province is sufficient during the following summer of the El Niño event. However, during the following summer of the La Niña event, the precipitation is generally abundant in the south of the Yangtze River and deficient in the north of the Yangtze River.