The vast majority of theories on maintaining the diversity mechanism stem from research on plant communities.As for the species coexistence theory based on plant communities generalized to fish community,there are a lot of questions.Meanwhile,in the case where todays fishing pressure,as well as a variety of habitat environment have changed,research on coexist mechanism of fish populations has important practical significance for the protection and utilization of fishery resources.This study select two fishes of cyprinidae(Cirrhina moitorella and Xenocyprininae)with similar resource requirements as research objects.Analyzing the differences in the occurrence of their larvea resources from the fields of population structure of the species,regeneration capacity on the occurrence of larvea resources.Explaining the coexistence mechanism of the two species combined catched data.Clarify the difference of the occurence of lervea resources on the two populations coexistence under the same predator and trapping pressure.Finding a breakthrough to elaborate fish community diversity maintenance mechanism and provide a theoretical basis for the protection of fishery resources.