ObjectiveTo study the relationship between mutation of the p53 gene, p21 gene and bacteria Lform in gallbladder carcinoma. MethodsForty cases of gallbladder carcinoma and 40 cases of chronic cholecystitis were studied by using Gram staining and immunohistochemistry (SP method) to detect the positive rate of Lforms antigen, p21 and p53 protein overpression. And the relationship between the expression of p21 and p53 in Lform infection positive group and that in Lform infection negative group was discussed. ResultsThere was no statistical difference between the Lform positive rate in patients with gallbladder carcinoma with Gram staining and immunohistochemistry (Pgt;0.05). The positive expression rate of p21 and p53 in gallbladder carcinoma was 62.5%(25/40) and 65.0%(26/40) respectively. The expression values of p21 and p53 in chronic cholecystitis was 2.5%(1/40) and 5.0%(2/40) respectively, which was significantly different from that of gallbladder carcinoma (P<0.05). The expression of p21 and p53 was significantly higher in Lform infection positive group than in that with Lform infection negative group (P<0.05). ConclusionBacteria Lform may be one of the direct factor leading to mutation of p53 and p21 during gallbladder oncogenesis.