Food composition and tract morphology of Apodemus agrarius mantchuricus and Cricetulus barabensis manchuricus in the plantation of Lower Nenjiang Valley was examined and compared to reveal whether the two species can co-exist through resources partitioning and how the two species adjust their digestive tract morphology to co-survival under the stress of competition and lower temperature.The contents of stomach were checked and sorted as leaves,stems,flowers,roots,seeds and insects to determine the food preferences of each species.The results showed that both of the two species mainly fed on fresh stems,leaves,seeds and insects,but the frequency of stems and leaves in stomachs of C.b.manchuricus was higher than that of A.a.mantchuricus,while the frequency of seeds,roots and insects was on the other hand.Adapted to food composition,both the length and the weight of stomach,caecum and large intestine of C.b.manchuricus were significantly larger than that of A.a.mantchuricus,which was the adaptive variation of C.b.manchuricus to its food resources with higher cellulose and lower quality.There were significant interspecific differences in small intestine,the small intestine length of C.b.manchuricus was shorter while the weight was larger than that of A.a.mantchuricus.These results indicated that the two co-existed rodent species have the different food selection pattern,while the different features of digestive tract morphology are the functional response to the partitioning of food resources.