Abstract:During a survey of freshwater diatoms from Shibadukeng stream in the Xianju National Park, Zhejiang Province, China, a newly recorded diatom, Encyonema ventricosum var. hankensis (Skvortzov) Rodionova & Pomazkina was recorded. Based on the application of light microscope (LM) and scanning electron microscope (SEM), E. ventricosum var. hankensis was identified and described here in details. The morphological differences between Zhejiang population and two Russia populations and other similar Encyonema species were compared. In addition, the habitat characteristics of Encyonema ventricosum var. hankensis in Shibadukeng stream were supplied in our paper. The results show that: (1) E. ventricosum var. hankensis valves strongly dorsiventral, dorsal margin broadly arched, ventral margin moderately undulant, apices capitate, deflected to the ventral margins. (2) E. ventricosum var. hankensis Zhengjiang population has a stigma on the dorsal side of the center area, while the Lake Khanka population and Lake Baikal population are no recorded. (3) E. ventricosum var. hankensis is found in Lake Khanka and Lake Baikal, and this is the first report from the freshwater in China.