To investigate the inhibition of total ginsenosides (TG) on right ventricular hypertrophy induced by monocrotaline(MCT) and explore the effects of TG on extracellular-regulated kinase(ERK) signal transduction in rat.Methods:Male Sprague Dawley rats were randomly divided into the normal group,MCT group and 20 mg/(kg·d),40 mg/(kg·d),60 mg/(kg·d) dose TG treatment group.Ventricular hypertrophy index(RVHI) was measured by the weight ratio of RV to left ventricle plus septum,and by observing the ultrastructural changes of myocardial cell with transmission electron microscope.The ERK1 mRNA and mitogen-activated protein kinase phosphatase-1(MKP-1) protein expression of right ventricle tissue were detected by real-time RT-PCR,Western blotting.Results:TG treatment could significantly reduce RVHI,RVW/BW.The swollen and misshapen mitochondria could be improved by TG.TG also could down-regulate ERK1 mRNA expression and enhance MKP-1 protein expression.Conclusion:TG could significantly attenuate MCT-induced cardiac hypertrophy in rat by suppressing ERK Signaling pathway.