Abstract: The QinghaiXizang Highway crosses a length of 720 km permafrost regions, in which there are four types of permafrost: quasisteady permafrost, basically stable permafrost, thermal unstable permafrost and extreme thermal unstable permafrost. Subgrade disease has perplexed the normal use of QinghaiXizang Highway with permafrost degradation since the completion of asphalt pavement in 1985, and different sections of the road have experienced 35 regulation projects. Climate predictions and simulated calculations indicated that the annual mean temperature of QinghaiXizang Plateau may rises 2.2—2.6 ℃ in the next 50 years, and the permafrost degradation will be more serious. The great decrease of stable road sections and remarkable increase of unstable sections will bring new damage to the normal operation of QinghaiXizang Highway. Based on the research achievements in last decades, the preliminary subgrade treatment measures in different road sectors were proposed by considering the background of future permafrost degradation, providing reference for freeze injury management of QinghaiXizang Highway.

Key words: climate change, permafrost, countermeasures, QinghaiXizang Highway