Objective:To investigate the relationship of TNF-A-863 and CGRP979 gene polymorphisms with the susceptibility to severe chronic periodontitis in Chinese.Methods: Buccal swabs were collected from 100 adult patients with severe chronic periodontitis and 118 healthy adult controls.DNA was extracted from each subjects of the two groups.PCR-LDR technique was used to identify the genotypes of TNF-A-863 and CGRP979.The difference in the genotypes between the two groups was analyzed by statistics software.Results: The genotype of TNF-A-863 was mainly TNF-A-863 A/C in patients with severe chronic periodontitis and TNF-A-863 C/C in healthy controls.There were significant differences in TNF-A-863 distribution between the two groups(P<0.05).We also found that there were significant differences in genotype distribution of CGRP979 between the two groups (P<0.05),with A/G predominating in patients with severe chronic periodontitis.Conclusion: TNF-A-863 polymorphism is associated with severe chronic periodontitis; A/G of the CGRP979 loci might be a factor for severe chronic periodontitis.