Abstract: A uranium mine in Hunan is an important production base of uranium resources in China, and the ecological environment of this mining area is damaged to an extent owing to its mining activities for many years inevitably. Distribution and ecological characteristics of the ostracod from the mine were analyzed, and radioactive contamination condition of surface water in and around the mine was evaluated using the fauna. Cypridopsis vidua distributes in the stream and river, and Helerocypris incongruens lives in the river only, with not high abundance of both species. The value of abundance and total abundance of the both species can reveal the change of uranium concentration of water body, which decreases with the increase of uranium concentration, and vice versa. Negative correlation between value of species diversity index of Shannon-Wiener and uranium concentration of water is obvious, which suggests that the uranium content of water can be indicated by the value. The index with low value obviously indicates that the surface water environmental quality of the area need to be refined, and radioactive contamination of the mine should be paid more attention adequately.