AimTo study the mechanism of ABZ,ABZSX and ABZSN on Ascaris Suum. MethodsThe activities of enzyme complexes in mitochondria were detected by spectrophotometer for the study of effects of ABZ, ABZSX and ABZSN on the anaerobic respiratory chain of enzyme complexes in mitochondria of Ascaris Suum muscle and rat liver. ResultsThe activity of succinate CoQ reductase in Ascaris muscle mitochondria was apparently suppressed by ABZ ,ABZSX. Conclusion Preliminary study on the mechanism and toxicity of ABZ through enzyme studies,in order to find a more effective and satisfactory drug with low toxicity for clinical use.