Through statistics and analysis of historical material from 1850 to 1949 in Guanzhong area, the paper studied the change，grades and causes of the droughts disaster. The result indicates that the droughts altogether had 56 times in the area, once average 1.78 years from 1850 to 1949, in which the droughts from 1920 to 1934 were the most frequent. In this area，the moderate droughts were main and accounts for 57.1% of the total number of droughts, and the serious droughts and worst droughts were 10.7% and 8.9% of the total number of droughts. The droughts had obvious seasonal difference and the droughts occurred in summer were the most, and that occurred in spring and autumn taken second place，and that occurred in winter was the least. The typical continental monsoon climate was the natural background for which the droughts occurred. In the Guanzhong area，the worst droughts and the serious droughts were created by the remarkable reduction of mean annual precipitation; The mild droughts and the moderate droughts mainly were created by the uneven precipitation assignment, sometimes following the certain reduction of precipitation.

Guanzhong area; droughts; droughts graduation