Abstract: Drought is a regional phenomenon in which the available water is below normal level on a certain time scale. The basic characteristics of drought are high frequency, long duration, and wide range of influence. Xinjiang is a typical arid and semi-arid region of China. Under the background of global warming, the loss of drought disasters in Xinjiang has shown a trend of expansion. In order to strengthen drought monitoring and assessment in Xinjiang, the RDI index was used to analyze the drought characteristics on seasonal scale and annual scale based on the daily precipitation and evapotranspiration data of five meteorological stations in Altay, Yining, Urumqi, Hetian and Hami Prefectures in Xinjiang. The RDI index is simple to calculate, sensitive to drought, and has strong stability. The paper analyzed the intensity, frequency, time and trend of drought in the five regions. Finally the direction of drought assessment in Xinjiang was pointed out which should be developed to forecast in order to reduce the loss of drought in Xinjiang. The results showed that the drought intensity and frequency of the five regions on the annual scale and the four seasonal scales were slightly different, but there were different degrees of humidification. Urumqi City had the highest degree of humidification and Hetian Prefecture had the lowest degree of humidification. From the seasonal point of view，the degree of humidification in the summer and autumn in Altay region was higher, but lower in spring and winter. The humidification in both Yining and Urumqi was more obvious in summer and winter but lower in spring and autumn. The humidification in spring, summer and autumn seasons in Hetian and Hami were higher than that in winter.

Key words: Xinjiang, reconnaissance drought index (RDI), drought, different time scales