Permafrost change under the climate warming was certified in Qinghai–Tibet Plateau, whatever permafrost degradation or ground temperature rising (Guodong and Dramis, 1992; Shaolin, 1993 and Qingbai and Changjiang, 1995; Tong Changjiang, 1996; Yongjian, 1998). From the 1970s to the 1990s, the ground temperature of seasonally frozen soil and of sporadic permafrost raised 0.3–0.5 °C, mean annual ground temperature of continuous permafrost raised 0.1–0.3 °C (Shaolin, 1993 and Shaoling et al., 2000). Permafrost with mean annual ground temperature around 0.0 to −0.5 °C is being quickly warmed and thinned down. Permafrost base in Jingxiangu raised 10–15 m, mean annual ground temperature raised 0.5–0.8 °C (Shaoling et al., 2000 and Jin et al., 2000).

 

The northern boundary of permafrost was retreated 0.5–1.0 km towards south, southern boundary 1–2 km towards north under the effect of the climate change (Changjiang and Qingbai, 1996). Permafrost areas in the Qinghai–Tibet Plateau are decreased 10,000 km2 in the recent 30 years (Li and Cheng, 1999). At the same time, the results of numeric simulation (Shuxun, L., Guodong, C. and Dongxin, G., 1996. The future thermal regime of numerical simulating permafrost on Qinghai–Xizang (Tibet) Plateau, China, under climate warming. Science in China (Series D) 39 4, pp. 434–441.Shuxun et al., 1996) and aided GIS regional modeling (Li and Cheng, 1999 and Qingbai et al., 2000) testified permafrost change related to climate warming. However, no one has more detailed data of ground temperature monitor in Qinghai–Tibet Plateau, especially the monthly and interannual change data of permafrost ground temperature. In this study, results of the ground temperature monitored for seven sites are analyzed, and recent permafrost temperature change is mainly discussed.

It is very important to analyze the change of the active layer and the permafrost thermal regime for Qinghai–Tibet Plateau. Formerly, there is only few data of monitoring to analyze the response of the active layer and the permafrost to climate change in Qinghai–Tibet Plateau. The monitoring data of the permafrost thermal regime with seven sites from 1995 to 2000 make it possible to analyze this response relationship.

The monitoring data is used to analyze the recent change in the thickness of active layer, the subsurface temperature, the near permafrost surface temperature, and the permafrost temperature at the depth of 6 or 8 m. The results show that their changes have a better accordance with air temperature change. The climate change has an impact on the change of the active layer and the thermal regime of the permafrost. The change of the active layer and the thermal regime of the permafrost can indirectly explain some features of climate change