Published data on the association between XPD Lys751Gln and Asp312Asn gene polymorphism and lung cancer risk are inconclusive.To derive a more precise estimation of the relationship,a meta-analysis was performed.A total of 22 studies including 15507 subjects for XPD Lys751Gln genotype and 13198 subjects for XPD Asp312Asn genotype were involved.For XPD Lys751Gln genotype,significantly elevated lung cancer risk was associated with two variant genotype (for CC vs.AA: OR =1.26,95%CI =1.12-1.42,P =0.473 for heterogeneity; for C allele carriers vs.AA: OR =1.18,95%CI =1.08-1.36,P =0.732 for heterogeneity).In the stratified analysis by ethnicity,significantly increased risks were found among Caucasians not in Asians.For XPD Asp312Asn genotype,significantly elevated lung cancer risk was associated with two variant genotype (for AA vs.GG: OR =1.24,95%CI =1.09-1.42,P =0.104 for heterogeneity; for the A allele carriers vs.GG: OR =1.35,95%CI =1.13-1.57,P =0.219 for heterogeneity).In the stratified analysis by ethnicity,significantly increased risks were found among Asians not in Caucasians.In the subgroup analyses by smoking status,there were no significant associations among non-smoker subgroup,however,in smoking group the significantly increased lung cancer risks were found.This meta-analysis suggests that the XPD Lys751Gln and Asp312Asn gene polymorphism are associated with lung cancer risk,the C allele of XPD Lys751Gln genotype is an increased risk factor for developing lung cancer among Caucasians and in smokers,and the A allele of XPD 312 genotype also is an increased risk factor among Asians and in smokers.