Anthracycline is a standard drug for the treatment of breast cancer. However, anthracycline has great cardiotoxicity. Some patients stop chemotherapy during severe chemotherapy and even undergo serious heart failure. At the same time, there is lack of clinical study on whether aerobic exercise can reduce the cardiotoxicity of chemotherapy drugs. The purpose of this study is to investigate the effects of aerobic exercise on the cardiac function of patients with breast cancer after anthracycline therapy. The results showed that the control group LVEF decreased significantly. In addition, the E/A value decreased and the DT interval prolonged in the control group, show that anthracycline on myocardial damage, and the observation group LVEF increased significantly (P<0.05), the results show that aerobic exercise can improve heart function, and to a certain extent, it could reverse the damage of chemotherapy drugs on the heart.