The value of two-dimensional strain echocardiography for assessing left ventricular regional systolic function in breast cancer patients who were treated with epirubicin was evaluated. A total of 116 breast cancer patients were divided into 3 groups: Thirty-eight patients in group A were given epirubicin (Epi) of 120-340 mg/m(2), 42 patients in group B received epirubicin of > or = 360 mg/m(2), and 36 patients after surging without chemotherapy served as the control group C. High frame rate two-dimensional images were recorded from apical long-axis view, four-chamber view, two-chamber view of left ventricle. Peak systolic strain of left ventricular subendocardial myocardium was measured using two-dimensional strain software. The conventional echocardiographic parameters were also obtained. Conventional echocardiography showed there was no significant changes in conventional echocardiographic parameters among the three groups (P>0.05). Two-dimensional strain echocardiography revealed that the peak systolic strain of left ventricular subendocardial myocardium in group A was reduced in some segments as compared with the controls (P<0.05). The peak systolic strain of left ventricular subendocardial myocardium in group B was reduced significantly as compared with group C (P<0.05), but that was reduced in group B just in some of the segments as compared with group A (P<0.05). It was concluded that two-dimensional strain echocardiography could early and sensitively display the effects of epirubicin-induced cardiotoxicity on the systolic function of left ventricular subendocardial myocardium, and early monitor the epirubicin-induced cardiotoxicity.