Abstract: The soil weathering degree of the Liao River Basin was studied on the basis of CIA index. It is shown that the soil weathering degree is generally very low in the Liao River Basin and there is no much difference between the deep and surface layers of the soil. The element spatial distribution of the deep and surface layers of the soil is U-type. The element content in the east is higher than that of the west, while it shows the lowest in the center. The weathering degree of the paddy soil and black soil is the highest in all types of soil, on the contrary, the aeolian sandy soil and fluvo-aquic soil show the lowest degree. In the case of geomorphologic one, the CIA value of the plain area is the highest with soil weathering degree higher than that of the mountain hilly area, the hilly and low mountain areas.