Objective This study aims to observe the protective effects of ginsenoside Rb1 on vital organs in rats with septic shock and reveal its mechanism.Methods Eighty-four Sprague-Dawley(SD)rats were randomly divided into three groups:sham,cecal ligation and puncture(CLP),and CLP/0.04mg /g ginsenoside Rb1.16 rats from each group were randomly chosen for observing overall survival rate and mean survival time for 7 days after CLP model had succeeded 6 rats from each group were randomly chosen for records of arterial blood pressure by carotid artery cannula connected to a pressure transducer and monitor.The rest 6 rats from each group were killed 4 hours after CLP and blood was collected for arterial blood gas analysis; the liver and lung tissue samples were dehydrated and embedded in paraffin,and then stained with hematoxylin‐eosin (HE)following by observation of pathological changes; the expression of Toll like receptor 4(TLR4)mRNA in myocardial tissue was determined by reverse transcription-polymerase chain reaction (RT‐PCR); the concentration of plasma tumor necrosis factor‐α (TNF-α)was measured with enzyme-linked immunosorbent assay (ELISA).Results 1.The 24,36 and 48 h overall survival rates in ginsenoside Rb1 group were higher than that in CLP group respectively.Compared to CLP group,the overall survival rate of ginsenoside Rb1 group increased significantly (P<0.01).The same is true of the mean survival time.2.Mean arterial blood pressure went down continuously both in CLP group and ginsenoside Rb1 group after CLP operation and reached the lowest point at 10h.There was significant difference both in sham group and ginsenoside Rb1 group when compared with CLP group (P<0.05 and P<0.01 respectively).3.The arterial blood pH in ginsenoside Rb1 group(7.27±0.07)was higher markedly than that in CLP group(7.13±0.05)(P<0.05).The arterial blood PO2 in ginsenoside Rb1 group (103.6±0.5 mmHg)was higher markedly than that in CLP group (95.1±1.9 mmHg)(P<0.05).4.Pathological changes:In CLP group,pathology showed swelling,degeneration,necrosis and neutrophil infiltration in the liver cells.While in ginsenoside Rb1 group,pathology showed swelling,mild degeneration,slight neutrophil infiltration but no obvious necrosis in liver cells.Moreover,in CLP group,there was swelling in alveolar epithelial cells,thickening in alveolar septum,expansion and congestion in capillaries,microthrombosis,congestion and edema in pulmonary interstitial,diffuse infiltration of neutrophils and diminished alveolar space with heavy inflammatory exudation.In ginsenoside Rb1 group,there was slight neutrophil infiltration in small vessels and capillaries,and wild edema in pulmonary interstitial without obvious thickening in alveolar septum or exudants in pulmonary interstitial.5.Treatment of ginsenoside Rb1 markedly decreased TLR4 mRNA expression in myocardial tissue(P<0.01).6.Treatment of ginsenoside Rb1markedly decreased the concentration of plasma TNF-α at 4 h (P<0.01).Conclusions Ginsenoside Rb1 improved the survival rate of septic shock in rats,ameliorated arterial PO2 and pH and also protected the liver and lung tissue in septic shock rats.Ginsenoside Rb1 may make it by down-regulating the expression of TLR4 mRNA and inhibiting the produce of TNF-α.