Abstract:As affected by the local topographical condition, soil moisture and thermal properties in the Daxingan Mountains varied largely, and soil types and vegetation in the region appeared to be the typical high-cold forest wetland with middle scale landscape feature. There were four types of soils from the local watershed divide to the low flood plain, i.e., sedge meadow soil, gray forest soil, Baijiang soil and dark brow forest soil. Obvious freeze-thaw process occurred in the forest wetland of the Daxingan Mountains, whereby the soil moisture content and phase varied significantly. Large soil moisture storage was observed merely in the surface horizon of forest soil in high relief during the freezing period, whereas obvious change in soil moisture content and phase was observed in the meadow soil in low relief. The water retention curve of Baijiang soil is very smooth, suggesting minor water change. The thin soil horizon developed in the mountain ridge and foot leads to a weak water retention capacity, except the litter layer(O horizon). When the litter layers are destroyed by human disturbances, serious soil erosion will occur.