Abstract: Objective To explore the association between telomere length and the risk of lung cancer.Methods Relative telomere length in genomic DNA extracted from peripheral blood leukocytes was measured with quantitative polymerase chain reaction among 145 lung cancer patients,145 healthy controls,and 145 coke-oven workers(exposed group).Results Telomere length in lung cancer patients was significantly shorter than in controls(1.24±0.88 versus 1.47±1.06,P=0.028).The exposed group exhibited a significantly shorter telomere length(0.94±0.72)than lung cancer patients(P=0.005)and healthy controls(P<0.001).When the subjects were categorized into quartiles based on the telomere length of healthy controls,the risk of lung cancer was found to increase as telomere length shortened(Ptrend <0.001).Compared to the individuals with long telomere length,individuals with short telomere length had a significantly increased risk of lung cancer(adjusted odds ratio=2.337,95% confidence interval:1.413-3.866).Furthermore,telomere length in the controls was significantly shorter in association with aging(P<0.001).Conclusion The results suggest that shorter telomere length may be associated with a higher risk of lung cancer and could be used as an early marker for susceptibility to lung cancer.