Abstract: A system of polysuitability and a method of quantitative appraisal of soils are used in Aksu River valley. The system and the method can evaluate not only the soil Suitabilities to agriculture, forestry, and animal husbandry and the suitable grades, but also the limitative factors and their limitation levels. The results reflect the potential productivity corresponding with the polysuitability possessed by the majority of the soils.
The main procedures of evaluation of the soils, on the basis deciding evaluation factors and their power coefficients and quantizing every factor, are realized with the aid of two algorisms in the model designed for the evaluation：The first one determines the suitabilities of the soils and their grades, the second ascertains the limitative factors and their limitation levels.
In the way mentioned above, ＂Map of Evaluation of soils in Aksu River Valley＂(1:200,000) is made. The distributions of the soils with different suitabilities and their areas can be gotten from the map.