In this paper, sub-region classification method was proposed to deal with the distribution of permafrost because of the impact of complex terrain. The results showed that the area of permafrost was 1 681.4 km2, accounting for 66.7% of the whole area. The transitional and sub-stable permafrost were the major types of permafrost, accounting for 50.8% of the whole area; unstable permafrost was accounted for about 11.4% of the total area, yet the percentage of stable and extreme-stable were smaller relatively, the percentage was 4.4% and 0.2%, respectively. A change was that seasonal frozen ground changed into unstable permafrost, then transitional permafrost, then substable permafrost, then stable permafrost, and extremely stable permafrost eventually with the increase of elevation.