Introduction: Antibody secretion in human may be the result of the changes in protein structure, or polymorphism in human thyroid peroxidase (TPO) gene that are the reason for presence of the Anti TPO. In this study we examined the association between of A1936/G exon11 polymorphism of TPO gene in respect to Anti-TPO level and in a sample population of Tehran. Materials and Methods: We enrolled 190 individuals with 47±2 y an average age of case-control groups. PCR-ARMS was used to amplify the segment of exon11 polymorphisms. Results: In exon 11, the genotype frequencies were in conformity with the Hardy-Weinberg expectation. The results of this study show that the frequencies were 0.7298 for the G allele and 0.2710 for A allele. The presence of the G allele is significantly associated with increased anti-TPO level (GG: 238±57 IU/ml vs. AA: 74±33 IU/ml, P<0.05). The G allele frequenc in the group with anti-TPO>100, was higher than that of the A allele. Conclusion: The results indicated that G allele carriers of exon 11 are exposed to increased Anti-TPO levels higher than A carriers.