Abstract: One series of temperature index and two series of flood/drought degrees in the north and south of Jiangsu Province are established. The major conclusions are as fllows.1. Since 200 A. D. until the end of 14 th century, it was warm in the former period and cold in the later period. There were three coldest sub-periods in the later period, for instance, from the end of 15 century to the beginning of the 16 th century, middle and later period of 17 th century, middle and later period of 19 th century.2. There was a heavy drought period from the end of 12 th century to the beginning of 13 th century since 800 A.D.. And then a relative humid period occurred from the middle and later period of 13 th century to the middle of 17 th century when a huge climatic abrupt (from the 1230’s to the 1260’s) happened since the last 2000 years in the south of Jiangsu Province.3. There was a relative drought period in the north of Jiangsu Province from the end of 16 th century to the beginning of 20 th century since 1400 A.D., and relative humid forwards and afterwards.4. The change of temperature can be divided 4 stages during the last 100 years, in which mean annual temperature obviously rose after the end of the 1980’s. Annual precipitation is typically shown on the periodicity of 30 years and 11 years in the southern and northern Jiangsu Province respectively. At present, the precipitation is shown in the normal and much more situation.