Abstract: The spore morphology of 6 species of the family Pottiaceae were observed by light microscope and scanning electron microscope: (1)Anoectangium thomsonii, (2)Weisia controversa, (3)Bryoerythrophyllum recurvirostrum, (4)B. yunnanense, (5)Totula muralis , (6)T. mucronifolia. The spore characteristics are different in proximal face and exine ornamentation. It showed heredity differentiation among the different genera and species in Pottiaceae. But the spores of 6 species are similar in shape, exine thickness and size. It showed that Pottiaceae may be a natural classification. The spores of Pottiaceae is more advanced than Sphagnum. However it is more primitive than gymnosperm and angiosperm in the evolution of aperture.