【英文摘要】Permafrost and marshes are widely distributed in the Da and Xiao Xing'anling (Hinggan) Mountains, Northeastern China. They are interdependent, forming a symbiotic permafrost，marsh complex. On the basis of several investigations and 2-year-period observations in the field, this research report analyses the affecting factors on and mechanisms of the development and degradation of permafrost-marsh symbiotic complex. In the viewpoint of macroscopic scales. The symbiosis of permafrost and wetlands is displayed in the coincidence in the spatial distribution. In the mesocale viewpoint, it is demonstrated in the nutual reliance of permafrost and wetlands in ecosystem functions. In the viewpoint of micro scales, it is illustrated in similar and interdependent vertical structures in heat, moisture and mass balances. A multi-level criterion nomenclature system of the symbiotic complex system was proposed.Through the analysis of observational data, this article focuses on analyzing the influences of vegetation and the peat layer on the permafrost-wetland symbiotic complex. According to the research, the types of vegetation are the internal drive for the development and degradation of the symbiotic complex. The vegetative impact of can reach depths as much as 4 m, and strong thermal effects penetrates to depths at least of about 1.6 m. Peat layer is functionally and structurally the key components for the symbiotic complex. It is observed that peat layer has a thermal diode effect on the development and preservation of permafrost. Climatic variations have significant polynomial impacts on ground temperatures. However, their influence dampens sharply and strong until with 0.5 m depths. When internal drives and external factors works against each other, the thermal stability of the permafrost-wetlands symbiotic systems decreases rapidly, and its degradation of is intiated. Based on observational data and using the SHAW model. Using the finite element method and assuming a climate warming rate of 0.048 C a?1, the ELM was combined with the unsteady-state heat conduction model to simulate permafrost temperatures at present, and to predict those after 50 and 100 a. According to the environmental features of the symbiotic complex, the measures for the environmental protection and management were put forward.