Abstract: Under the background of climate warming, the authors studied the variation characteristics of 0℃ critical temperature in alpine region of Qinghai, in order to rationally explore husbandry climate resources. Based on the daily average air temperature data of Guinan meteorological bureau from 1961 to 2017, the authors analyzed the variation characteristics of the first day, the final day, the duration and accumulated temperature with ≥0℃ by the methods of sliding average method, linear tendency estimation and M- K mutation analysis. The results showed that: the first day when the temperature steadily passed 0℃ in Guinan during 1961-2017 showed an insignificant advance trend and the final day showed an insignificant postponed trend; the duration showed a significant increase trend with a rate of 1.48 d/10 a; the accumulated temperature with ≥0℃ had an extremely significant increase trend with a rate 30.2℃· d every 10 years; the first day and the final day when the temperature steadily passed 0℃ had no mutations; the duration had a mutation from few to many in 1985; the accumulated temperature had a mutation from less to more in 1994.