According to runoff stroage data from 1971 to 2010, five level standards were established by using mean and standard deviation method. Appionted at the runoff characteristics of dependent random variables, taking all orders autocorrelation coefficients as weights, Markov chain model was used to predict the runoff state in the next year. The results show that the method can provide a new feasible way for regional and long-term runoff prediction, and is direct, accurate and simple.