Based on 6-hourly (02:00, 08:00, 14:00 and 20:00 Bejing time (BJT)) air temperature data of 38 meteorological stations over Tibet from 1981 to 2014, the spatial-temporal distribution and climate abrupt characteristics of air temperature are analyzed by using the methods including linear regression and Mann-Kendall test. Also, the correlation between the change rates of surface air temperature and latitude (longitude, and altitude) is discussed. The results showed that, the seasonal air temperature in Tibet exhibits unanimously increasing trend with a rate of 0.14-0.80 ℃/10a during the past 34 years, and the most significant increase occurred in winter. In terms of the rate per decade for the 6-hourly air temperature observations, 08:00 BJT during summer experienced the highest increasing rate, while 14:00 BJT showed the highest values for the other three seasons . The maximum rate for the increasing air temperature ranges from 0.36 ℃/10a (P < 0.001) to 0.94 ℃/10a (P < 0.001). Among all the 38 stations, there were only 32% (about 12) showing the peak time with the highest rate of changes at 08:00 BJT air temperature, which are predominantly located in much of Qamdo, Ngari prefecture and at weather stations such as Nagqu, Lhasa and Xigazê, while the rest of weather stations showed the highest increasing rate at 14:00 BJT. In spring and autumn, as the increasing rate was related to longitude, it has a larger rate in western than that in eastern Tibet. In winter, the highest increasing rate of air temperature occurred in the regions with higher altitudes and latitudes, and the higher increasing rate of air temperature was observed at higher latitudes in summer. As for the decadal characteristics of 6-hourly air temperature, the 1980s experienced negative anomalies, compared with positive anomalies in the first decade of the 21st century. Additionally, it was found with abrupt change test that at the annual and seasonal scales most of hourly air temperatures have abrupt change. For instance, the abrupt change of all four hourly air temperatures in summer occurred in the first decade of the 21st century. In winter, the abrupt change of air temperature at 02:00 and 08:00 BJT occurred in the late 1990s, while that at 14:00 and 20:00 BJT was found in the first 10 years of the 21st century. As can be seen in the article, many factors such as topography, various meteorological elements in the plateau and the atmospheric circulation play important roles in the surface air temperature change in Tibet.