Objective To determine the inhibitory effect of TFP5 on the hyperactivity of cyclin dependent kinase 5 (Cdk5) induced by high glucose and its protection for the pancreatic beta cells from apoptosis. Methods After TFP5 was delivered into mouse insulinoma line 6 (Min 6), the expression of TFP5 was detected in the cells by Western blotting and immunofluorescence staining. Then, the cells were treated by low (5mmol/L), high glucose (25mmol/L)+empty vector (EV), and high glucose +TFP5, respectively. Cdk5 activities were measured by immune precipitation and isotope labeling. The level of insulin secretion were detected with ELISA; and the apoptosis of Min 6 cells were analyzed by Western blotting. Results (1) Our results indicated the derivation of TFP5 peptide from p35 and its sequence. (2) TFP5 was well expressed in the Min 6 cells. (3) Cdk5 activity was significantly lower in the high glucose+TFP5 cells than in the high glucose+EV cells (P＜0.01); the insulin secretion level in the high glucose+TFP5 cells was significantly higher than that in the high glucose cells (P＜0.01). (4) In the high glucose cells, the expression of Bax was increased while that of Bcl-2 was decreased, and the ratio of Bax/Bcl-2 was increased (P＜0.01, vs the low glucose cells), indicating the increase of cell apoptosis. However, the expression of the 2 proteins was opposite, and the ratio was decreased in the high glucose+TFP5 cells, showing lesser apoptotic cells (P＜0.01, vs the high glucose cells). Conclusion TFP5 inhibits the hyperactivity of Cdk5 induced by high glucose, protects pancreatic cells from apoptosis, and recovers the insulin secretion. Therefore, it may have a potential therapeutic agent for type 2 diabetes targeting on Cdk5.