Aim To investigate the protective effect of pretreatment with Gentiopicroside on transverse aortic constriction （TAC） -induced myocardial hypertrophy. Methods 40 male C57BL mice were randomly divided into two groups: sham group（n6） and myocardial hypertrophy model group（n32）.Mice in myocardial hypertrophy group were operated transverse aortic constriction.24 h later,the mice in myocardial hypertrophy group were randomly divided into 4 groups: myocardial hypertrophy model group,Gentiopicroside high,middle and low dose group,which were given physiological saline and different doses of Gentiopicroside for 4 weeks.Echocardiogram was performed to assess the cardiac function changes.Heart weight to body weight ratio（HW/BW）,heart weight/tibial length（HW/TL）,left ventricular end-diastolic diameter（LVEDD）,left ventricular end-systolic diameter（LVESD）,left ventricular ejection fraction （LVEF） and left ventricular fractional shortening （FS） were measured.The expression levels of atrial natriuretic peptide （ANP）,brain natriuretic peptide （BNP）,and β-myosin heavy chain （β-MHC） in heart tissues and the size of cardiomyocytes were also observed. Results Compared with myocardial hypertrophy model group,the LVEDD decreased 24.9% in Gentiopicroside group（especially dose up to 10.0 mg/（kg·d）,the LVESD decreased 26.3%；while the LVEF increased 49.5%,the FS increased 62.6%,respectively（P<0.01）.The HW/BW and the cardiac myocyte cross-sectional area showed a decrease in Gentiopicroside group compared with myocardial hypertrophy model group（P<0.01）,while still increased significantly compared with the normal control group.The expression of ANP,BNP and β-MHC in Gentiopicroside group were lower than those in myocardial hypertrophy model group（P<0.05）. Conclusion Gentiopicroside can intervene the progress of pressure overload-induced myocardial hypertrophy in C57BL mice.