To compare the effects of black soybeans and Sojae Semen Praeparatum(SSP) on the activity of dipeptidyl peptidase Ⅳ(DPP-4) in the mouse model of type 2 diabetes.Methods:The model of type 2 diabetes was induced in mice by high-sugar and high-fat diet combined with streptozotocin(STZ).After modeling，the mice were randomly divided into a normal control group，a model control group，a positive control group，low-，medium-，and high-dose black soybeans groups，and low-，medium-，and high-dose SSP groups.The blood sugar changes of the mice were monitored during drug administration.The serum levels of total cholesterol(TC)，triglyceride(TG)，high-density lipoprotein cholesterol(HDL-C)，and low-density lipoprotein cholesterol(LDL-C) were detected by the enzymatic method.The DPP-4 activity，glucagon-like peptide-1(GLP-1)，and glucose-dependent insulinotropic peptide(GIP) in serum were determined by ELISA.Results:The blood sugar in the positive control group and the high-dose SSP group decreased significantly during drug intervention(P<0.05).Compared with the results in the model control group，only the HDL-C level increased in the medium-dose SSP group，and the levels of TC，TG，LDL-C，and HDL-C in the high-dose SSP group changed significantly(P<0.05).Compared with the model control group，the positive control group，the high-dose black soybeans group，and medium-and high-dose SSP groups showed increased inhibition rates of DPP-Ⅳ activity in serum(P<0.01).The levels of GLP-1 and GIP in the positive control group and the high-dose SSP group were higher than those in the model control group(P<0.05).Conclusion:SSP extract can reduce blood sugar，blood fat，and other biochemical indicators in the mouse model of type 2 diabetes to varying degrees，inhibit DPP-4 activity，and increase the levels of GLP-1 and GIP.