Aim To evaluate left ventricular function in patients with non-ischemic cardiomyopathy (NICM) and ischemic cardiomyopathy (ICM) by two-dimensional speckle tracking echocardiography (2D-STE). Methods From September 2014 to February 7,4 patients with enlarged hearts and reduced left ventricular systolic function admitted to the Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology were selected. According to the results of coronary angiography, the patients were divided into NICM group (n＝43) and ICM group (n＝41). Routine echocardiography and 2D-STE were performed to analyze left ventricular function in patients with NICM and ICM. Results The left ventricular ejection fraction (LVEF) in NICM group was significantly lower than that in ICM group (P＜0.05), but there was no significant difference in left ventricular end-diastolic diameter, interventricular septum thickness and left ventricular posterior wall thickness between the two groups. 2D-STE results showed that there was no significant difference in global longitudinal strain value between NICM group and ICM group. In NICM group, regional longitudinal strain value (RLS) in apical segment increased (P＜0.05), while RLS in basal segment decreased (P＜0.01). The results of receiver operating characteristic curve showed that the basal RLS/(middle RLS＋apical RLS) ratio had the highest value in distinguishing NICM from ICM, and the area under the curve was 0.792, the cut-off value was 0.47, the sensitivity was 63.4%, the specificity was 88.4%. Conclusions Patients with NICM and ICM have different characteristics of two-dimensional strain ultrasound. 2D-STE strain analysis is helpful in the differential diagnosis of NICM and ICM.