Abstract：Objective To assess the left ventricular systolic function in patients with hypertrophic cardiomyopathy by three-dimensional speckle tracking imaging(3D-STI).Methods 19 healthy volunteers in the control group and 19 patients of HCM in the case group were selected. The three-dimensional full-volume dynamic images of left ventricle were acquired and stored. 4D-auto LVQ were used to obtained the horizontal rotation curves, the global twist and torsion of the left ventricle. Results Compared with the control group,the global twist and torsion of the HCM group were increased, while the global longitudinal strain was significantly decreased (P<0.01). Basal plane rotation angle were significantly increased in the HCM group. Conclusion Torsion increases with long-axis strain decreases when myocardial function is impaired in HCM patients. 3D-STI could be used as a technique to reflect the changes of left ventricular systolic function at all planes in HCM patients.