Some factors which influence the upper limit of permafrost in Qinghai-Xizang plateau are analyzed and prevention measures for mad bed stablization of Qinghai-Xizang highway are provided.

• 摘要通过青藏高原多年冻土地区气温、植被及人为活动等因素对多年冻土上限影响的分析，提出了青藏公路路基稳定性的防护措施。