Abstract:  Spermatodesms of Gampsocleis gratiosa and G.. sedakovii was studied by differential interference contrast （DIC） microscope, which is of significance to study the reproductive isolation mechanism and reproductive biology of the related species. The results indicate that the spermatodesms of G. gratiosa and G.  sedakovii, which are transferred from the male to the female by spermatophores, are considerably different between the male and the female even in the same species. In testis the sperm is single. In vasa deferentia, seminal vesicles and spermatophores, sperms are grouped together in bundles to form spermatodesms There is a mucous cap that encloses the head of the spermatodesms. In female spermatheca, the spermatodesms are feather-shaped with a median axis. The morphology of spermatodesms shows little difference between the two species.

Key words: Gampsocleis gratiosa, Gampsocleis sedakovii, spermatodesms, morphology, microstructure, differential interference contrast （DIC）