Objective To investigate the tumor suppression and immune regulation mechanism of cisplatin and gin-senoside Rh 2 in 4T1 breast cancer tumor-bearing mice.Methods 4T1 breast cancer was divided into model group,Rh 2 group and cisplatin group,combination group(cisplatin+Rh 2).The general status of mice was recorded,the patho-logical structure of tumor tissue was observed,the protein expression levels of inflammatory factors IL-2,IL-2,IL-10,IFN-γ and multi-drug resistance protein Pgp were detected by immunohistochemistry,and the tumor suppressive effect and immune regulation mechanism of the combination were evaluated.Results The mice in the model group,Rh 2 group and the combination group had good living condition,while the cisplatin group had depressed mental state,de-creased exercise ability,withered hair,decreased appetite and diarrhea.Compared with the model group,the mice had decreased body weight,tumor volume,tumor necrosis area,IL-2 and IFN-γ protein levels,IL-10 protein levels were significantly lower(P<0.05);P gP protein levels were significantly higher in cisplatin group(P<0.05),and no signifi-cant differences among other groups(P>0.05).Conclusion Combination therapy can strengthen the therapeutic effect by enhancing the immune function and the multi-drug resistance to cisplatin.This combination therapy has important clinical application value and provides new ideas for the discovery of combined immunotherapy drugs from traditional Chinese medicine.