Abstract:The forecast modes of society yields(high, medium and lower stage) and weather yields(bumper, general and poor harvest)for crops by means of IOSDASA fuzzy classififcation, Bayes distinguishing method and step-wise regression were estabilished and reported in this Paper. The result Showed that the similar percentage of simulant forecast was more than 97% based the statistic of crop yields over the years and the correlation analysis of yields with social and weather elements.