Abstract: Based on analyses of the meteorological data at 29 meteorological stations in Qinghai Province from 1959 to 2003, the corrected Palmer drought severity index (PDSI) was calculated and analyzed. The results show that the PDSI is more objective in comparison with Z index in dryness/wetness monitoring. Most of droughts were light in Qinghai, the interannual alternations of dryness/wetness in summer and autumn were more frequent with larger change ranges in comparison with winter and spring. The drought trend in autumn was the severest, and the probability of light drought was the largest in winter and spring. Moreover, the total drought area in Qinghai Province decreased in spring, the light drought area increased in summer, but the medium and heavy drought area decreased, and the severe drought area increased in winter and autumn during 1959-2003.

Key words: Qinghai Province, PDSI, dryness, wetness