Abstract:It is high altitude, cold and much permafrost area along Xin-Zang highway (219 national highway). The most permafrost from Shiquan river to Ritu is seasonal frozen soil. It is easy threatened by permafrost such as frost swelling, salivary ices, thaw settlement. In this paper, we tell the forms, reasons of permafrost diseases and the main prevention measures. We obtain that it is effect to solve the seasonal frozen soil that we make use of filling replacement and paving geo-textile. The last, we suggest that we should enhance environment protection, reduce the man-made disturbing permafrost in the process of construction and strengthen the monitoring along the road.