Abstract: After carrying out the disposal of historical data of drought disasters occurred in the Tarim River Basin during the period of 1949-2010, the drought frequency, serious degree and period in the drainage basin were analyzed using the spectrum analysis and cycle analysis. The results showed that 59 times of drought disasters were totally recorded in the drainage basin from 1949 to 2010, in which the severe drought, serious drought, moderate drought and slight drought were 10 times, 25 times, 11 times and 13 times, and their proportions were 16.96%, 42.37%, 18.64%, 22.04%, respectively. The droughts over level Ⅲ occurred 35 times, and they occurred once every 1.75 years and accounted for 59.32% of the total drought disaster years. The drought disaster rate over 20% occurred in 14 years in the Tarim River Basin during the period of 1990-2010, the drought occurrence rate and drought disaster rate were the highest in 1993, and they were 37.5% and 17.3% respectively. The drought occurrence rate over 25% and drought disaster rate over 15% occurred in 3 years in 1993, 2001 and 2002 respectively, and they occurred once every 7 years. The average areas suffering from drought at different levels and occurred every 5 years were 2.65×105, 2.22×105, 3.23×105 hm2 and 3.53×105 hm2, and the average disaster areas were 1.22×105, 1.05×105, 1.78×105 hm2 and 2.31×105 hm2, respectively. There were the 2year, 3year, 6year and 13year quasiperiods of drought in the Tarim River Basin during the period of 1950-2010 years, especially the 2year and 3year ones were very significant, and their confidences were as high as 99% and 95% respectively.