Abstract: With the high resolution lattice data (daily maximum and minimum temperatures) of CN05.1 from 1961 to 2015, 6 extreme temperature indexes were calculated. Through the trend analysis and Mann-Kendall (M-K) mutation test, the spatio-temporal varation of extreme temperature events in the Qinghai-Tibet Plateau is investigated. The results show that the overall distribution of extreme maximum temperature, extreme minimum temperature and warm diurnal index had an upward trend, and the tendency rates were 0.25℃/10a, 0.42℃/10a, 2.14d/10a. Compared with extreme maximum temperature, the linear warming trend of extreme minimum temperature was more obvious. The changes of ice index(ID), frost index(FD) and cold night index(TN10) showed a downward trend, the tendency rates were −3.09d/10a, −4.75d/10a, −2.31d/10a. In terms of spatial distribution, the warm trend of extreme maximum temperature in Qinghai Province was the most significant, especially the Qaidam Basin was the warming center. In terms of temporal variation, the extreme maximum temperature, ice index(ID) and warm diunal index(TX90)has a sudden change in 1997.