Objective To analyze the cardiac function of ischemic dilated cardiomyopathy (IDCM) and non-ischemic dilated cardiomyopathy (NIDCM) patients by the two dimensional speckle tracking echocardiography (2D STE) . Methods According to the results of coronary angiography, 41 IDCM patients and 42 NIDCM patients were taken as the research groups 24 normal patients were taken as the control group. Retrospective analysis of the cardiac ultrasound characteristics of those patients was taken. The 2D STE was used to measure the left ventricular global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS)of each group, and strain parameters between the groups were compared.Results Compared with the IDCM group, LVEF was significantly lower in the NIDCM group (P<0.05); GLS in both groups was much lower than that in the control group，but GLS between the NIDCM group and the IDCM group demonstrated no significant difference (-9.9±3.4% vs. -9.6±3.3%; P >0.05), the GCS and GRS in the NIDCM group were significantly lower than those in the IDCM group (-5.4±2.6% vs. -7.0±2.5%; 7.5±4.5% vs. 10.7±4.7%, both P <0.05). The results of ROC curve demonstrated that the GRS has the largest AUC value (AUC: 0.701), with the cutoff 8.53%, the sensitivity 66%, and the specificity 74%. Conclusion The left ventricular myocardial strain of IDCM and NIDCM patients are significantly decreased, and GRS could be used to help differentiate NIDCM from IDCM.