Abstract: Arid-hot valleys are special ecological type in southwest China. Land degradation/desertification is very severe in the arid-hot valley of the Jinshajiang River, the upstream of the Yangtze River, and threatens residents' living and sustainable development of national economy. The study on land desertification presently include type, distribute, cause of formation, harm, process and principle of forming. Land desertification degrees are still determined qualiatively. In order to take some countermeasures, rapid and accurate evaluation to the land desertification in this region should be done. The degrees of land degradation/desertification are determined by element analysis and multiplayer fuzzy evaluation in accordance with the complexity and fuzziness of land ecological system. The study shows those as following: Physiognomy, soil and vegetation is important factors for evaluation to land desertification in the arid-hot valley of the Jinshajiang River. According to the evaluation criteria system land desertification degrees are determined quantitatively with fuzzy evaluation. The evaluation result is accurate and reliable. It can tell us not only the degree of land degradation/desertification, but also its developing tendency and provide scientific basis and support of policy decision for the prevention of Land degradation/desertification and bringing it under control.