Three kinds of drought indexes are introduced and assessed, these indexes are all able to be used for abnormal dryness calculating and drought monitoring. But to the actual, the anomalous precipitation index reflect more lighter, and the dryness degree index reflects too sensitive, Z index can be more accurate to reflect the drought disaster. So a drought intensity index and a drought area index are developed based on the Z index, and these two indexes are used to analyze the dryness year by year from 1952 to 2004 in Zhejiang Province. It indicates that there is a increases of drought frequency since 1990′s in Zhejiang Province, the drought is heavier also, and drought in autumn occurred more frequently especially. 2003 is the second severe drought year after 1967 since 1950′s.