A biologically based model of both practical and theoretical significa nce was developed to simulate rice growth.On conditions with suitable water and fertilizers,the crop growth processes were simulated by considering solar radiat ion and temperature.Its spatial scale is leaf level,and temporal scale is hourly .The model can simulate instantaneous canopy photosynthesis.The model was valida ted using data from geographically sowing experiment.It is showed that the model can interpret 92 5%-95 8% of the changes of dry matter accumulation with d evelopmental stage and sowing date in different climatic areas.Using regular met eorological data,including solar radiation,we studied ecological acclimation of hybrid rice numerically in the north,middle,and south subtropical zones and Yunn an Guizhou Plateau.The result shows that Yunnan Guizhou Plateau is a high dry matter production area for middle rice,because of higher radiation,lower tempera ture and longer growth period.In the south of China,the early and middle rice is low productive,because of higher temperature and shorter growth period,but it i s a high productive area in late rice.Also in Changjiang River Valley,the suitab le sowed late rice has higher productivity provided the high temperature in summ er and low temperature in autumn in its middle and late period of growth can be avoided.