Up to the present, neither the studies carried out nor the models developed athome or abroad for simulating the growth of various crops have made a breakthrough orcould be put into operation by the meteorological services. This is because special obser-vational data are required and complicated parameters have to be calculated. In this pa-per, based on the crop physiological and agrometeorological theories and consideringcrop photosynthesis, respiration and allotment of assimilated products, a simplifiedmodel is presented for the growth of late rice. In this model only conventional meteoro-logical data are needed with the pentad as the length of time-step.