Using the method of conversion probability and the prediction principle of maximum probability,the conversion principle of random time sequence state of early frost date,latest frost date and monthly precipitation at Akesu city in Xinjang during 1954-1995 was analysed.Combining the initial distribution of every sequence state,the prediction model was given.The forecast for every factor in 1996-1999 shows that the method′s prediction effect and applying effect are better.