Based on observed data from 36 meteorological stations from 1961 to 2013, taking relative moisture index as a drought index, the temporal and spatial distribution of drought was analyzed by using Kriging method. The results showed that the annual index decreased significantly (P<0.01) from 1961 to 2013, drought severity was steadily increased, and the drought grades also showed an increasing trend. The index decreased significantly in spring and autumn (P<0.01), and more obviously in autumn. While the index in winter increased significantly, but the range was narrowed. The index in all seasons increased from southwest to northeast, with the southwest region as high risk region. There was negative correlation between the index and temperature, solar radiation, respectively, and positive correlation between the index and relative humidity, wind speed and precipitation, respectively.