Objective:We aimed to establish a model to select dipeptidyl peptidase IV（DPP-IV）

and to test the inhibitory rate of the seven compounds.Method:DPP-IV was extracted from cultured Caco-2 cells and the values of absorbance（A） were tested in different activity units which were to evaluate the relation between the activity of DPP-IV and the value of A by the curve of activity-A.Sitagliptin as a positive control was used to evaluate the selected model.The derivatives from sitagliptin and the compounds were estimated inhibitory activity by the model.Result:The activity of DPP-IV was correlated to the value of A in a certain range.The IC50 values of sitagliptin

JD-1 and JD-2 were 18.354 nmol·L-1

3.4 μmol·L-1 and 2.6 μmol·L-1

respectively;the range of inhibitory activity for the compounds was between 21.45% and 27.77%.Conclusion:The IC50 of sitagliptin tested by this selected model is close to the value reported

which proves availability of the model.and meanwhile

the compounds estimated in this study contain inhibitory effect.