This paper describes a small microgastropod fauna from the Lower Triassic Yelang Formation at the Zhongzhai section, Guizhou Province, southwestern China. A new species Polygyrina zhongzhaiensis sp. nov. and two other species of Polygyrina (P. depressa Wang and P. sp.) are described and illustrated. The shell beds predominantly composed of the microgastropods are interpreted to indicate a stressed environment where salinity appears to have been abnormal, and oxygen and food supply were deficient.