Objective To evaluate left ventricular systolic and diastolic function of breast cancer patients undergoing anthracycline chemotherapy by strain and stain rate parameters and to explore the application value of recognition of myocardial damage in those patients with different ECG performance and negative 2DE results during anthracycline chemotherapy by 2D-STI technology. Methods 38 breast cancer patients treated by anthracycline chemotherapy and 30 controls were recruited. Echocardiography were performed before and after1, 2, 3, 4 chemotherapeutic cycle (T0, T1, T2, T3, T4). 38 breast cancer patients were divided into normal ECG group (12 cases) and abnormal ECG group (26 cases) according to ECG results.2D-STI strain and strain rate parameters included the longitudinal peak systolic strain of three-layers myocardium (GLSendo, GLSmid, GLSepi), standard deviations and maximal differences of time to peak regional LS（Tls-SD，Tls-dif） in all 18 segments, longitudinal peak strain rate in early diastolic (LSRe) and E/LSRe. Results Compared with E/e’ of T0, T1 T2 or T3, E/e’ of T4 increased significantly in both the normal ECG group and abnormal ECG group (p<0.05), but there was no significant difference between the two groups at the same chemotherapy cycle (p>0.05). Compared with GLSendo、GLSmid、GLSepi、Tls-SD、Tls-dif、LSRe and E/LSRe of T0, T1, T2, and T3, GLSendo、GLSmid、GLSepi、LSRe of T4 decreased significantly and Tls-SD、Tls-dif、E/LSRe of T4 increased significantly both in the two groups(p<0.05). There was no significant difference between the two groups in GLSendo、GLSmid、GLSepi、LSRe of the same chemotherapy cycle (p>0.05). But E/LSRe of T4 in patients of normal ECG group was significantly higher than that of abnormal ECG group. Conclusion Strain and strain rate parameters by 2D-STI may be more sensitive than conventional ultrasound parameters in identification of chemotherapeutic-related cardiac dysfunction. The left ventricular systolic and diastolic function of breast cancer patients were impaired after anthracycline chemotherapy, regardless of with or without abnormal ECG. For patients with abnormal ECG results, left ventricular diastolic function may impair more severely. In addition, E/e"", LSRe and E/LSRe may be more suitable to assess left ventricular diastolic function in breast cancer patients undergoing anthracycline chemotherapy.