In order to obtain a better insight of the possible threat of environmental factor to wildlife, especially to amphibians, we studied influences of dicofol on heart rate in R. nigromaculata by applying biological signal recording and monitoring system. R. nigromaculata was injected in ventral lymph follicle in different doses of dicofol solution, and then observed the changes of heart rate after 7 days. The results showed that with the concentration of dicofol solution increasing, the heart rate, systolic tension and diastolic tension changed. The aim of this research is to discuss the cause of dicofol on the physiology in frogs. It can be concluded that dicofol affects the electronic activity of the frog’s heart.