Nile tilapia (Oreochromis niloticus) has successfully invaded many areas of the world, threatening the survival of native fish and the structure and function of the water ecosystem. In order to control the population of the Nile tilapia in wild conditions, an organophosphate drug called “Mie fei ling” was screened out for the specific toxicity on Nile tilapia. In this study, the effect of “Mie fei ling” on Nile tilapia and other common fish was verified through the acute toxicity test. Meanwhile, the median lethal concentrations of “Mie fei ling” to the Nile tilapia (length, 4.0±0.3 cm; wet weight, 2.5±0.4 g) at 24, 48, 72 and 96 h were determined by the method of semistatic test, and the safe concentration in the environment was also estimated. The result showed that “Mie fei ling” had significant effects on poisoning the Nile tilapia (P<0.01). The Nile tilapia exposed to “Mie fei ling” 0.10, 0.17 and 0.20 mg·L^-1 for 96 h all died, while the other species including the grass carp (Ctenopharyngodon idellus), mud carp (Carrhina molitorella), crucian carp (Carassius auratus), loach (Misgurnus anguillicaudatus), zebrafish (Danio rerio), and the White Cloud Mountain minnow (Tanichthys albonubes) swam normally with no symptoms of toxicity. The 24 h, 48 h, 72 h and  96 h LC₅₀ values of Nile tilapia were 0.167, 0.077, 0.057 and  0.043 mg·L^-1 respectively and the safe concentration was 0.0043 mg·L^-1. These results suggested that “Mie fei ling” could be used to specifically control the wild Nile tilapia population in small water bodies.