The red-eared slider (Trachemys scripta elegans) is a worldwide invasive species.Field studies conducted in Nanjing, Guangdong, and Hainan of China, using trapping, mark-recapture and radio tracking revealed that T.s.elegans presented at all sites and made up the majority (60.2%-93.2%) of turtle communities.The female biased sex ratios ranging from 20∶100 (Hainan) to 50∶100 (Guangdong) in the feral population were highly consistent with the results of market surveys in Hainan (21∶100), and a high ratio of shell inscription (37.2%) suggested the population is still relying on Buddhist release.However, the high loss rates (43.6%-100% and 51.4%-80.0% for Nanjing and Hainan, respectively), mainly due to human collection, also indicated human activities as a double-edged sword to the feral population of T.s.elegans.The population of native species, such as Chinese stripe-necked turtle (Mauremys sinensis), was much smaller than that of T.s.elegans.A high rate (50.0%) of carved carapace, which were relied on human release too, and a high semiyearly loss rate (36.4%-77.7%) implied the endangered situation of M.sinensis.Over fishing affects native species negatively and collection of introduced sliders does not replace the demand to native turtles, which implies a possible apparent competition.Our research quantified the effect of human harvest to introduced turtles for the first time, and showed that eating the exotic species could not eradicate it.