Abstract: Because of non-rectangular hyperbolic photosynthetic model being more active response to photosynthesis, its integration for the single leaf area is performed in the paper. And, the model is applied to the calculation of the dry matter weight in the paddy fields. The accuracy of calculation is higher than that of the integration formula with rectangular hyperbolic photosynthetic model. The experiment of the parameter sensitivity is conducted. Furthermore, some problems of the seed breeding and numerical simulation are indicated