Objective:To evaluate left ventricular myocardial systolic dyssynchrony in the patients with hypertrophic cardiomyopathy(HCM)by ultrasound speckle tracking imaging. Methods:Myocardial imaging of 35 HCM patients (HCM group)and 30 healthy subjects(control group)was collected,and their regional time to peak systolic strain in longitudinal,radial,circumferential motion were measured respectively. The data was compared and analyzed between the two groups. Results: In control group,no significant difference was found in time to peak longitudinal,radial and circumferential strain. Compared to control group,time to peak longitudinal strain(Tl)was significantly delayed,not only in the hypertrophic segments,but also in the segments with normal thickness. Time to peak radial strain (Tr)and time to peak circumferential strain (Tc)was also delayed,but more severe delay was found in longitudinal direction. Conclusion:Ultrasound speckle tracking imaging can quantitatively evaluate the left ventricular myocardial systolic dyssynchrony.