Olfaction is essential for fish to detect odorant elements in environment.The sense of smell plays an important role in locating food,navigating,detecting predators,and spawning migration.The olfactory function is produced by the olfactory transduction pathway and activated by the olfactory receptors through binding of odorant elements.In vertebrates,the olfactory receptor gene families are recently classified into five families,the main olfactory receptor(MOR),vomeronasal type-1 receptor(V1R/ORA),vomeronasal type-2 receptor(V2R/OlfC),trace amine-associated receptor(TAAR)and formyl peptide receptor(FPR).More than 50% of vertebrates are fishes,which own important biological status.However,there are few articles published in this field in China,although more and more attention has been focused and many findings have been reported.This review describes the recent advance in studying the five olfactory receptor gene families in fishes,and makes a discussion and a summary of the problems encountered during the research,as well as the corresponding measures to resolve them.Finally we open an outlook to the further study in olfactory receptor genes.We aim to provide references for the research on olfactory receptors of fish in China.