Objective: To evaluate transduction efficiency with recombinant adenovirus-mediated p53 (rAd/p53) therapy in a human colon cancer mouse model by intra-tumoral injection and intra-arterial delivery. Methods: The tumor pieces of human colon cancer SW480 were implanted in the livers of 45 nude mice. These mice were administrated with rAd/p53 by intratumoral injection and intra-arterial delivery. After 24 h, 48 h and 72 h rAd/p53 administration, 5 mice each group were killed with over anesthesia and their livers were removed. P53 expression and apoptosis of tumor and liver were assessed. Results: P53 expression and apoptosis of intratumoral administration group was higher than tail vein group and control group. Apoptosis and p53 expression of livers in three groups had no significant difference. Conclusion: p53 gene transduction efficiency and anticancer effect of rAd/p53 is much better by intra-tumoral injection than intra-arterial delivery. Objective: To evaluate transduction efficiency with recombinant adenovirus-mediated p53 (rAd / p53) therapy in a human colon cancer mouse model by intra-tumoral injection and intra-arterial delivery. Methods: The tumor pieces of human colon cancer SW480 were implanted in the Livers of 45 nude mice. These mice were administered with rAd / p53 by intratumoral injection and intra-arterial delivery. After 24 h, 48 h and 72 h rAd / p53 administration, 5 mice each group were killed with over anesthesia and their livers were Results. P53 expression and apoptosis of tumor and liver were assessed. Results: P53 expression and apoptosis of intratumoral administration group was higher than tail vein group and control group. Apoptosis and p53 expression of livers in three groups had no significant difference. gene transduction efficiency and anticancer effect of rAd / p53 is much better by intra-tumoral injection than intra-arterial delivery.