Objective To explore the efficacy of Yishen Yangyin Gujing Prescription[derived from Zuogui Wan(Bolus for Replenishing Kidney-Yin)]for the treatment of diabetic nephropathy in type 2 diabetes mellitus(T2DM)with qi and yin deficiency syndrome,and to observe its effects on inflammatory responses,pancreatic β-cell function and renal function.Methods A total of 162 T2DM patients with diabetic nephropathy of qi and yin deficiency syndrome who admitted to the Affiliated Hospital of Shaanxi University of Chinese Medicine from May 2020 to July 2023 were randomly divided into an observation group and a control group according to the random number table method,with 81 cases in each group.The control group was given conventional western medicine treatment for lowering blood pressure and renal protection,while the observation group was treated with Yishen Yangyin Gujing Prescription on the basis of treatment for the control group.The course of treatment for the two groups covered 12 weeks.Before and after the treatment,the changes in the outcomes of the two groups were observed,and the outcomes included the total scores of traditional Chinese medicine(TCM)syndrome,insulin sensitivity index,insulin secretion index,24-h urine total protein quantification(24hUTP),and serum levels of glycosylated hemoglobin(HbA1c),fasting insulin(FINS),fasting blood glucose(FBG),serum creatinine(SCr),blood urea nitrogen(BUN),transforming growth factor β1(TGF-β1),NLRP3 inflammasome,interleukin 6(IL-6),superoxide dismutase(SOD)and sphingosine-1-phosphate(S1P).After treatment,the clinical efficacy of the two groups of patients was compared.Results(1)After 12-week treatment,the total effective rate of the observation group was 93.83%(76/81),and that of the control group was 83.95%(68/81).The intergroup comparison showed that the efficacy of the observation group was significantly superior to that of the control group(χ2=9.163,P<0.05).(2)After treatment,the insulin sensitivity index and insulin secretion index in the two groups of patients were increased(P<0.05)and the total scores of TCM syndromes were decreased(P<0.05)when compared with those before treatment,and the increase of insulin sensitivity index and insulin secretion index as well as the decrease of the total scores of TCM syndrome in the observation group was significantly superior to that in the control group(P<0.05).(3)After treatment,the serum levels of HbA1c,FINS,FBG,SCr,BUN and 24hUTP in the two groups of patients were decreased when compared with those before treatment(P<0.05),and the decrease of the above indicators in the observation group was significantly superior to that in the control group(P<0.05).(4)After treatment,the serum TGF-β1,IL-6,and NLRP3 inflammasome levels in the two groups of patients were decreased(P<0.05)and the serum S1P and SOD levels were increased(P<0.05)when compared with those before treatment,and the decrease of serum TGF-β1,IL-6,and NLRP3 inflammasome levels as well as the increase of serum S1P and SOD levels in the observation group was significantly superior to that in the control group(P<0.05).Conclusion For T2DM patients with diabetic nephropathy of qi and yin deficiency syndrome,the combined use of western medicine and Yishen Yangyin Gujing Prescription treatment is helpful to alleviate inflammatory response,improve the function of pancreatic β-cells,regulate the blood glucose level,improve renal function,and enhance the clinical efficacy.