Abstract: The samples selected from 31 species which cover 10 genera of Chinese Hamamclidaccac. Stomalal apparatus in surl’acc view arc observed under scanning electron microscope (SEM). Results arc as follows: the features of ridges (Rim), in slomatal apparatus emerge a variable pattern between different subfamilies or genera. Three types and seven subtypes of slomatal apparatus under SEM arc recognized. They prove to be of very important information of systcmatics in the family.