The forecast model for population dynamics of Meriones unguiculatus and Cricetulus barabansis was built by using Markov chain, combining with optimization method (0.618) based on of population dynamics data of these two species that collected in Hohhot suburbs of Inner Mongolia from 1984 to 2004. And a forecast on the population dynamics of M. unguiculatus and C. barabansis in 2004 was made in this paper. The result showed that the forecast was corresponded to the field data accurately. The Markov model was applied to forecast the population dynamics of M. unguiculatus and C. barabansis for three years, from 2005 to 2007. The result showed that the model provided a handy, accurate and reliable method for the prediction on rodent population dynamics.