Abstract: Objective To investigate the differences in the expressions of miRNA-1（miR-1）and miRNA-133（miR-133）in the tissue of hypertrophic left ventricle of spontaneously hypertensive rats（SHR）. Methods17-week-old male SHR with left ventricle hypertrophy（LVH group,n=10）,8-week-old male SHR without LVH（SHR group,n=10）and 17-week-old male Wistar-Kyoto（WKY）rats（WKY group,n=10）were used in this study. HE staining was used to measure the pathological changes and quantitative real-time PCR（qRT-PCR）used to determine the expressions of miR-1and miR-133 in the left ventricular tissue. Results Compared with WKY group,systolic blood pressure（SBP）and diastolic blood pressure（DBP）were higher in LVH group and SHR group（188.5±13.6）,（152.3±10.8）vs（130.6±10.1）mm Hg,P＜0.01;（123.5±15.3）,（94.3±10.4）vs（74.3±17.4）mm Hg;P＜0.05. There were no statistical differences in left ventricular mass（LVM）/body mass and the transverse diameter of myocardial cells between WKY group and SHR group（all P＞0.05）. Compared with SHR group,left ventricular myocardial cells became marked hypertrophy,myocardial interstitium increased,LVM,LVM/body mass and transverse diameter of myocardium were larger in LVH group（956±33）vs（684±24）mg,（2.87±0.15）vs（2.17±0.14）mg/g,（15.32±0.61）vs（12.01±0.43）μm,all P＜0.05. In addition,the level of miR-1 significantly increased and the level of miR-133 significantly decreased in LVH group.Conclusion Different expressions of miR-1and miR-133 were detected in the left hypertrophic ventricular tissue of SHR and the level of miR-1significantly increased while the level of miR-133 significantly decreased.