Objective To explore the tumor suppressive effect of superantigen staphylococcal enterotoxin B (SEB) for mice beared by Lewis lung cancer cell (LLCC). Methods SEB gene expressive plasmid PCDH-SEB-GFP was constructed and transfected into LLCC and it was detected by Western blot. Tumor-bearing mice model was established by subcutaneous injection of LLCC and SEB expressive plasmid PCDH-SEB-GFP was successfully injected into the tumor to observe its suppressive effect on the growth of Lewis lung cancer in mice. Results SEB expression was detected after transfection of LLCC with SEB gene plasmid PCDH-SEB-GFP. Intratumoral injection of plasmid PCDH-SEB-GFP could significantly inhibit the growth of Lewis lung cancer in tumor-bearing mice. Conclusions Intratumoral injection of superantigen SEB expressive plasmid can inhibit the growth of Lewis lung cancer in mice. It deserves a further study that SEB gene can work as an exogenous antigen gene in immune gene therapy for lung cancer.