The pollinarium morphology of 17 species and 1 subspecies of Cynanchum were observed under light microscope(LM).The results showed that:(1)The sharp and size of pollinarium of Cynanchum were different from various kinds of species.The pollinia were sagging,and their shape were usually spheroidal,prolate,and perprolate.The average size of pollinia was long 327.2 μm×wide 183.9 μm.The shape of retinaculum were oblong,near roundness,near squares,and near triangle,and their average size was long 406.1 μm×wide 231.4 μm.(2)The caudicle of C.alatum was the least developed,while that of C.decipiens was the most developed.(3)The pollinarium morphology of C.atratum and C.officinale,C.corymbosum and C.verticillatum were similar.The results supported the treatment of Cynanchum Sect.Vincetoxicum in Flora Reipublicae Popularis Sinicae (Vol.63) and supported that Tylophora should be a unique group.It was considered that C.alatum was the false identification of C.callialatum in Flora of China (Vol.16),since the results in this paper showed their pollinarium morphology were different.