Abstract: Objective: To investigate the relation ship between helicobacter pylon(HP), mutant p53 expression in gastric cancer. Methods: Using immediate urease test and ELISA to detect HP, immuno histochemical staining to detect mutan p53 protein. Results: The positive rate of HP in gastric cancer and gasric precancerous conditions is higher than that of the other (P0.05), but comparing gastric cancer with precancerous conditions, the two positive rates of HP have no significant difference (P0.05). The positive rate of mutant p53 protein in gastric cancer is higher than in precancerous conditions (P0.05) HP positive gastric cancer has a higher positive rate of mutan p53 protein than HP negative gastric cancer (p0.05). Conclusion: HP inflammation and mutant p53 expression have a role in the development of gastric cancer. In gastric cancer HP inflammation has a connection with the expression of mutant p53 gene.