The micromorphological structure of bristle,wart and cutile ornamentation of cells of leaf apex and their neighbor cells of twelve mosses from the source area of Urumqi river were observed by LM and SEM.The results indicated that cells on the top of the leaf apex of most species of the species were transparent,longer and thinner than leaf cell,but with various shape;cell wall was sunken with irregular microgroove and fine particles when it was dry,but not always contracted.Margin of the leaf apex was involuted or twisted,and cell wall was thick with many small pores when it was dry.These characteristics are benefit to absorption of water and adaptive survival strategy for resisting hurt from long period cold and solar radiation.Types of leaf apex have little significance to the classification of family and genus of bryophytes,but the micromorphological structure of cells on the top of the leaf apex and shape,cell number and sunken degree of cell wall and micromorphological structure of wart,mastoid,cutile ornamentation and small pore of other cells are obviously different among different species in same genus,with certain meaning for classification of species under genus level.