Abstract: Based on the daily temperature data of 100 national meteorological stations over the Qinghai-Tibet Plateau from 1981 to 2020, the spatial-temporal distribution of temperature at different altitudes in the plateau in recent 40 years was studied. The results show that: (1) The average temperature, maximum temperature, minimum temperature and diurnal temperature range of the Qinghai-Tibet Plateau in the past 40 years were 4.01 ℃, 11.93 ℃, −2.29 ℃ and 14.22 ℃, respectively. The average, maximum and minimum temperature showed an increasing trend, with an average warming rate of 0.319 ℃/10a, 0.284 ℃/10a and 0.384 ℃/10a, respectively. The diurnal range of temperature showed a significant decreasing trend, and the average decreasing rate was 0.206 ℃/10a. The higher the altitude, the more obvious the downward trend. The spatial distribution of the climatic trends of average, maximum and minimum temperature was consistent, and gradually increased from the northwest to the southeast of the Qinghai-Tibet Plateau. (2) The average, maximum and minimum temperature of the Qinghai-Tibet Plateau showed a rising trend in the altitudes range of 2000~2999 m, 3000~3999 m and above 4000 m, and the average temperature showed the most obvious increasing trend above 4000 m. The diurnal temperature range showed a significant downward trend in the three altitude ranges, and the higher the altitude, the more obvious the downward trend. (3) The variation of interdecadal temperature with the increase of altitute in the plateau area was not consistant, but the decrease and increase of average, maximum, minimum temperature and diurnal range of temperature in all decades were the most obvious at altitudes above 4000 m. The average warming rate of average and minimum temperature showed an obvious increasing trend with the increase of altitude, and reached the maximum value above 4000 m, which were 0.339 ℃/10a and 0.441 ℃/10a, respectively. The average warming rate of maximum temperature and diurnal temperature range decreased with the increase of altitude, and reached the minimum above 4000 m.