Objective: The aim of the study was to improve the therapeutic effect for lung cancer using a synergetic strategy of adenovirus-based gene therapy combined with chemotherapy. Methods: A conditional replication adenovirus(CRAd) was employed to treat the A549 lung cancer cells and cisplatin-resisted A549(A549-DDP) cells. In vitro MTS / PMS assay were used to evaluate the cell viability. PCR were used to detect expression of Coxsackie receptor (CAR) and Multidrug resistance(MDR) gene. The in vivo anti-tumor effect of CRAd and cisplatin was evaluated using a subcutaneous mouse model. Results: The CRAd sensitizes A549 cancer cells to cisplatin. The mechanism of enhanced cell growth inhibition is associated with the increased CAR and MDR expression. Conclusion: Our approach is better than the conventional gene therapy and chemotherapy strategy.