Abstract: Having reviewed briefly the evaluation of the natural grassland resources of China, we turn our attention mainly to those factors that play an important part in the evaluation of these resources. A mathematical model of three-stage multifactorial evaluation of the natural grassland resources is proposed here by exploiting the relationships among those factors. This is the first time that such a mathematical model has been applied to the overall evaluation of these natural resources in China. To verify the accuracy of the model, we evaluated four types of the resources according to this model and a description of the process of computation in detail is given. It is proved that the model is highly accurate and is suitable for the evaluation of the natural grassland resources of China.