Abstract: Based on the accumulated thermal and radioactive effects from different leaves area on the growth and development of Myrica rubra, use the meteorological data and outdoor phonological observation data from 2004 to 2010 in Zhejiang Province, the meteorological data and development date of Myrica rubra in greenhouse in 2010, build a accumulated thermal and radioactive effect model to predict Myrica rubra development stages. Several data were used to validate the model. It proved that the simulated results agreed well with the observed ones. Based on the 1:1 line, the root mean squared error (RMSE) and R² were 0.03 cm and 0.99. The simulation results show that there was a positive correlation between rate of Myrica rubra development and increasing of leaves, in the case that 5, 10, 15 and 20 leaves were kept. The rate of Myrica rubra development decreased slightly when 25 leaves were kept, compared with the condition happened when there ware 20 leaves kept. Those indicated that leaf area was the key to effect the fruit growth and quality formation of Myrica rubra. It can be concluded that the model developed in this study can give satisfactory prediction of Myrica rubra development date and can be used for decision making for the production of Myrica rubra and providing for meteorological service.