摘要基于对多年来风火山地区的多年冻土资料，研究了天然地区和路基下的冻土上限变化情况以及多年冻土的融化状态，并定量分析了进入多年冻土内的热状况。

• Based on the several year data of permafrost in the region of Fenghuoshan Mountain, this paper not only studied the transformation of upper limit of permafrost in natural ground and roadbed but also the thawing of permafrost, and analysed quantitatively the status of heat which have entered permafrost.