Abstract: From 1961 to 2000 mean month reanalysis data from NCEP/NCAR and 160 station's month precipitation data from National Climate Center (China) have been used, analyzed by methods of linear tendency variety, correlation and vapors transportation. The time-space distribution features of year's or seasons marking area of drought tendency of climate transition zone in China mainland, and the relationship between East Asian summer monsoon and polar vortex activity. The results demonstrate:(1) Year's precipitation linear tendency was notable descend from mid-east of Inner Mongolia, Shanxi, Henan, eastern Shaanxi and Gansu to western Hubei, northwest Sichuan and Chongqing (among them include China climate transition zone), compose a climate drought area about 1/5 of China with remarkable descend area of China north, mid-south of northeast, around Bohai sea, Shandong and north of Jiangsu. In 1990's mean precipitation was 50-100 mm below normal in an area about 900,000 km2 precipitation decline sharply in summer and autumn. Year precipitation linear tendency remarkably raise in mid-lower reaches of Yangtze River, southeast inshore and Guangdong; (2) negative anomaly area of 1000-300 hPa vapor transportation in 1990's summer and 40 years climate drought area of China are similar;(3) Drought area connect with east of western China and north China, mid-south of northeast china, around Bohai sea, the reason is various. The correlation with weaken of activity at 30°N and its north of East Asia summer monsoon of influence China and Pacific polar vortex strength index from 1970's was revealed notablely.