Abstract: Palmer Drought Severity Index(PDSI) and Crop Moisture Index(CMI) were applied to diagnose drought process in Zhejiang Province.The results showed that long term climatic dryness/wetness events were captured by PDSI,and short term drought course of events by CMI.The monthly PDSI over the 41 observational stations in Zhejiang from Jan.1961 to Dec.2006 were analyzed with Experiential Ortho Function(EOF) method.The ranges of dryness/wetness in the middle Zhejiang were larger than in north and south parts.Converse changes of the dryness/wetness were found between the north and south,as well as between east and west parts because of geographical influence.Two clear dryness periods since 1961 were found,which occurred during early 1960's to early 1970's and during 2003 and present days respectively.

Key words: Zhejiang Province, Zhejiang Province, Drought, Palmer Drought Severity Index(PDSI), Crop Moisture Index(CMI), Experiential Ortho Function(EOF)