Abstract:Based on the precipitation,air temperature and evaporation data in Henan province during 1961-2009,the Standardized Precipitation Evapotranspiration Index (SPEI) was calculated,hence the strength of drought during different growth stage of winter wheat in Henan province was graded by the SPEI and divided into slight,moderate and extreme droughts.According to the growth characteristics,the growth period of winter wheat in Henan province are divided into early growth period,tillering stage,and turning green-heading-maturity period.The drought characteristics including interdecadal trend,coverage area,frequency,period and spatial distribution were analyzed and compared using Meteoinfo software,Morlet wavelet analysis,and linear regression method.Results show that the characteristics of drought in different growing stages of winter wheat were different,and the drought's frequency and intensity were various in different regions or years.But the slight drought takes up the maximum probability,while the extreme drought has the minimum probability,which is a common feature during all growth periods.The drought occurrence in Zhumadian City has the maximum probability in every growth period.The major periods of extreme point for drought during the whole growth period were about 10a.The SPEI increased in Henan in recent years,indicating a drought trend in future for Henan province.