Abstract: Objective: To investigate the effect of combining p15 gene transfection with TGF-β₁ on the proliferation and apoptosis of human esophageal squamous cell carcinoma cell line EC109. Methods: The plasmid pCDNA3.1 (+)-P15 was transfectcted into EC109 cell by the vector of liposomes and 10ng/mL TGF-β₁ was added after stable sieving to examine the exogenous p15 gene. The western blot method was used to determine the change of p15 proteins. MTT, colony formation, flow cytometry and transmission electron microscope (TEM) were used for determination of the effect of p15 transfecting TGF-β₁ on the proliferation and apoptosis of EC109. Results: Compared with the single application, the combination obviously inhibited the growth velocity and the colony formation rate was apparently decreased (P<0.01); limpid G1/S occurred clearly, the proportion of G1 phase was significantly increased (P<0.05), that of S phase was significantly decreased (P<0.05), and the rate od apoptosis was significantly increased (P<0.01) compared with either p15 transfected group or added TGF-β₁ group. It was also found under the transmission electron microscope that obvious apoptosis occurred in the combined p15 gene transfection with TGF-β₁ group. Conclusion: p15 Combination of p15 gene transfection with TGF-β₁ can further strengthen the inhibition and can induce the apoptosis on EC109 cells in vitro.