Abstract: Samples from Changchun-Siping highway, Changchun-Songyuan highway and North Changchun-Jilin highway were studied.Studied from microstructure of frozen soil, combining physicochemical tests and mechanical tests, the influence of properties of seasonally frozen soil in Changchun area on moisture movement is evaluated，which provides the experimental evidence for study of moisture movement of seasonally frozen soil and the road frost heaving and mudding in Changchun area. It is concluded from the experiments that the diameter of pore of seasonally frozen soil in Changchun area is mostly less than 5 μm, which is benefit for the migration of gravitational and capillary water. With high content of mineral substance, large cation exchange capacity, rich clay content, regular particle shape and great hydration specific surface area, it is benefit for the formation of hydration membranes. The external loads influence the moisture movement.And sample 3 has the largest quantity of moisture movement, then sample 1,and sample 2 the lest.

Key words: seasonal frozen soil, moisture movement, microstructure, content of soluble salt, exchange capacity of cation