Abstract: The content of chlorophyll is a very important assessment index in the growing situation of the wheat, especially under the condition that the wheat is influenced by the disease. So estimate its content of chlorophyll accurately is helpful to appraise the calamity rationally. The hyper spectrum technology of remote sensing has offered the abundant data source for obtaining physiological parameters of plant. This text uses the hyper spectrum data of wheat influenced by yellow rust in the area of Xiangfan, and utilize the method of regression analysis to establish relation model between the content of wheat chlorophyll and the data of wheat hyper spectrum influenced by yellow rust. The result shows that the model is satisfying.