Objective:To investigate the beneficial effects of ginsenoside Rg1 (Rg1) in the treatment of cardiac hypertrophy induced by transverse aortic contraction(TAC) and the potential molecular mechanisms in rats. Methods:Adult male SD rats were conducted in the study;twenty-four rats which are managed to present left ventricular hypertrophy(LVH) after TAC were randomly divided into two groups:the TAC group and the Rg1 group. Another 12 rats which was absence of the aortic artery ligated after analogous operation was included in the Sham group. The administration of Rg1 was conducted at 10 mg/(kg·d) for 4 weeks. After that,the left ventricular mass index (LVMI) were examined as hypertrophic parameters;left ventricle sections were stained with hematoxylin and eosin for ventricular wall thickness and myocardial microstructure. The mRNA transcription of ANP,BNP and HIF-1α was detected by Real-time quantitative PCR. The protein expression of HIF-1α was evaluated through Western blot test. Results:Compared with TAC group,the treatment with Rg1 significantly reduced the LVMI,the size of cardiomyocyte,and the mRNA expression of transcripts of ANF,BNP (P < 0.05,respectively). In the Rg1 group,the protein and mRNA levels of HIF-1α were significantly increased comparing to the control group(P < 0.05,respectively). Conclusion:Ginsenoside Rg1 attenuates the left ventricular hypertrophy and improves the cardiac function in the experimental rat model after TAC undertaken. This beneficial effects may be partially attributed to the increase of HIF-1α expression.