Abstract: The prevalent pattern of rice bacterial blight had been observed for 23 years in rice paddy fields in lower reaches of Ming River, and the dominant factor of the disease prevalence was definited.By using progressive regression,three forecasting models for analysing multi factor prevalence have been established. x2 examination showed that,the fitting probabilities of the theoretical with practical data were 99.5%,the historial conformable rate reached 91.4%～100%. The preliminary forecasting results by using these models in 1995 and 1996 were conformed with the practice which the disease was lightly occured in this area.