Abstract: Objective: To investigate the association between the polymorphisms of interleukin- 6 (IL- 6) and the susceptibility of lung cancer. Methods: Genomic DNA of 175 lung cancer patients and 200 healthy controls were extracted from the peripheral blood leukocytes. Then three fragments covering position - 174 、 position - 572 and position - 597 of the IL- 6 gene were amplified by polymerase chain reaction (PCR). The polymo- rphisms of patients were revealed by restriction fragment length poly-morphism (RFLP). Software Unconditional logistic regression model was used to analyze the statistical association of genotypes in three groups adjusted by gender 、 smoking and age. Results: No polymor-phism at position- 174 was dectected in any of the 375 participants. Only three partici pants with G/A genotype was found, others are G/G genotype (99.2%), no A/A genotype was revealed. A preliminary case- control analysis of the popula- tion revealed significant difference in genotype frequency of - 572 site polymorphism.Stratified by sex 、 age and history of smoking: male,age between 40 and 70, without smoking carrying with G/C or G/G will have decreased susceptibility to lung cancer. Conclusion: Our data suggest that there was significant difference in the polymorphism at position - 572 of the in ter-leukin- 6 gene promoter, the risk at lung cancer decreased.