Abstract: Objective To investigate the influence of p53 mutation status in tumor cells to the gene therapy of Adv-p53. Methods The mutation status of p53 gene in MCA-205 and Panc-02 cells was analyzed by SSCP -PCR and DNA sequence. The transduction ratio of adenovirus vectors was analyzed by flow cytometric analysis. Apoptosis of tumor cellstransfected with Adv-p53 was analyzed by TUNEL assay. Anti-tumor effect of Adv-p53 was examined in murine liver metastasis model. Results p53 gene in MCA-205 cells had a mutation in 769th base from G to T. p53 gene in Panc-02 cells had not a mutation. The transduction ratio of adenovirus vectors was higher inthat ofPanc-02 cells, but apoptosis after transfected with Adv-p53 was more significant in MCA-205 cells. Invitro experiment, growth of tumor cells was inhibited by Adv-p53 in MCA-205 cells，but not in Panc-02 cells. In murine liver metastasis model, the growth ofMCA-205 tumors was inhibited by intra-portal administration of Adv-p53, but the growth of Panc-02 tumors wasnotinhibited. Conclusion The anti-tumor effect of Adv-p53 was more significant in tumor cells with a mutation of p53 gene. The effect of gene therapy of Adv-p53 was influenced by p53 mutation status in tumor cells