A model for predicting seasonal yield of rubber (Hevea brasiliensis) tree was evolved using meteorological data, crop phenology and production of trees of clone RRIM 600 at Jose Bonifacio country, Sao Paulo state, Brazil close to 21 00'S, 49 42'W and 470 m above sea level. To quantify monthly and ten day basis yield response the model was adjusted considering the ratio of actual to potential yield as a productory of penalization by moisture and thermal factors. The monthly and decendial potential yield were estimated as a senoidal curve, which fits well to the seasonal periodicity of latex production. The best performance for the ten day basis model was found considering 100 mm of storage soil water and moisture factor expressed by the ratio of actual to potential evapo-transpiration, resulting in R2=0.73 and d-index = 0.90.