摘要:The authors have done some researches on the leaves and stems of potamogeton L. in Inner Mongolia by comparative classification by using the methods of morphology and anatomy. After having studied we found that they are ten species in Inner Mongolia. Among them, five species are belonged to cosmopolitans P. perfoliatus L., P. crispus L., P. pectinatus L., P. panormitanus Biv. and P. lucens L.; two eastern Asian sppcies: P. distinctus A. Benn. ao(?) P. malaianus Miq.; P. vaseyi Robbins is an East Asian-North American species) P. zosterifolius Schum. is an Eurasian species; one new species, P. acifolius Ma, is endemic to lnner Mongolia.