Based on the monthly temperature data at 7 stations in Gannan, Gansu Province, the variation characteristics of temperature in recent 40 years were a nalyzed. The results show that the abrupt change of the annual mean temperature occurred in the early of 1990s, the nighttime temperature increased in the end of 1980s, in the 1990s the temperature of daytime and nighttime increased co ncurrently, the main reason for the abrupt change of temperature in the area is co ncurrent increase of the daytime and nighttime temperature in the 1990s. It is found that a quasi8year period is the main period of the mean temperature, maximum temperature and minimum temperature before the mid 1980s. The mean tempera ture of autumn began increasing from the end of 1980s, the mean temperatures of summer and winter began increasing from the early of 1990s.The daily maximum tem perature, daily minimum temperature and daily range of temperature vary with sea sons.