Abstract: Objective :To study the therapeuetic effect of combined gene therapy with herpes simplex virus thymidine kinase (HSY-tK) and interleukin-2 (IL-2) on pleomorphic adenoma cells of salivary gland. Methods :IL-2 and HSY-tK gene were transfected into human pleomorphic adenoma cells of salivary gland using recombinant adenovirus vector. The efficiency of transfection was checked and gene was expressed using RT-PCR methods. The cell inhibition after transfection was verified by light microscope and MTT. Results :The proliferation of pleomorphic adenomas cells transfected HSY-tk and IL-2 gene was inhibited and the cell survival rate was decreased to 37.7% and 66.0% respectively in 5 days. However, when IL-2 gene combined with HSY-tK/GCY system, the killing effects was significantly stronger (P<0.05) and the cell survival rate was decreased to 21.5U. Conclusions : Combining IL-2 gene with HSY-tK/GCY system for gene therapy in pleomorphic adenoma cells of salivary gland is a valuable method.