Objective To explore the suitable chemotherapy measures in different Clonorchis sinensis infectiosity endemic ar-eas. Methods The interventional groups and control groups were set up in the heavy,moderate and light C. sinensis infectiosity areas in Guangdong Province,respectively. In the intervention groups,the chemotherapy was administered among all the residents aged above 3 years in the heavy endemic areas,the chemotherapy was given among the focus populations in the moderate endemic areas,and the chemotherapy was administered among the residents infected with C. sinensis confirmed by stool examinations in the light endemic areas. No measures were carried out in the control groups. Results One year after the interventions,the C. sinensis infection rates of the interventional groups decreased by 47.90%,86.52%and 100%,the abnormal rates of liver B ultrasonic ex-aminations decreased by 26.50%,31.00%and 100%,the ALT abnormal rates decreased by 48.70%,62.30%and 100%,and the AST abnormal rates decreased by 55.50%,39.90% and 100% in the heavy,moderate and light endemic areas,respectively. There was no decreasing trend of above-mentioned indexes in the control groups. Conclusion In the different C. sinensis infectios-ity endemic areas,the different chemotherapy measures should be carried out.