The monthly mean temperature data at 160 stations in China during 1951—2005 and 59 stations in Jiangsu during 1961—2004 are used. On the basis of the analysis of seasonal and inter-annual variations, the inter-annual and inter-decadal variations of summer temperature in Jiangsu are emphatically studied in this paper. It is found that the summer temperature in Jiangsu was basically in a cooler period from 1970s to earlier stage of the 1990s, and in a partial hot period in 1960s and after the middle and later periods of 1990s; the summer temperature abnomaly shows the quasi-six year, quasi-nine year inter-annual periodic variations and sixteen-year inter-decadal periodic variations. The temperature trend in northwest and southeast of Jiangsu shows rising, the trend appears depressed in other areas.