The field tests on stable infiltration rates of typical soil and their affecting factors conducted in the 50 counties and cities, which belong to the severe soil-water losing region of upstream and midstream areas of Changjiang River were studied by the doubl-ring method. The results show that steady infiltration rate varies regularly in different regions and in different soil types. Sichuan basin and Bijie area are the high-value regions of stable infiltration rate; South Shanxi Province, South Gansu Province, Three Gorges Reservoir-area and Danjiang Reservoir-area represent mid-value regions; The downstream area of Jinshajiang River and the red-earth rolling terrains of East Human Province and south Jiangxi Province belong to Low-value area. The infiltration rate Changes with soil types, ranged from high to low in order of yellow soil, lime soil, purple soil and red soid; the change of it with soil bulk density presents a negative correlation, but the relations between it and porosity, water-stability aggregate magnitude of air dry soil(diameter over 0.25 mm), organic content and ratio of silt to clay, respectively, are positive ones.