The weather characteristics, circulation background and the formation mechanism of the abnormal lasting high temperatureand drought event occurred in Chongqing in summer of 2006 are analyzed by using reanalysis data of NCEP, OLR and SST data. Re2sults show that the abnormity ofWest Pacific Subtrop ical High resulted in this lasting high temperature and drought event, and this ab2normity ofWest Pacific Subtrop ical High was greatly affected by such factors as the abnormal position and strength of Southern AsiaHigh, changes of Polar vortex and subtrop ical jet stream, warmingWest PacificWarm Pool and so on.