Abstract: The paper introduces a canopy photosynthesis and a dry matter accumulation model of winter wheat．The moodel mainly considers the influence 0f the environm ental factors on crop photosyn thetic process，quotes the simple empirical partitioning pattern and establishes a dry matter accumulation mod e1．The results of mod eling are compared well with the experimental results through the statistical an alysis by RMSE whose values range from 15 tO 100．It indicates that the model has a good function tO simulate the photosyn thesis and the dry matter accumulation in winter wheat under water stress conditions ．