Objective: To investigate the susceptibility of the cyclin D1 gene(CCNDl)G870A polymorphism to childhood acute lymphoblastic leukemia(ALL) in a southern Chinese population. Methods:Three hundred and forty-six children with ALL and 520 matched cancer-free controls were genotyped for the CCNDl G870A polymorphism by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP)and sequencing. Results:The distribution of three CCND1 G870A genotypes among cases was not significantly different from that among controls. Among ALL patients,the phenotype distribution was not signifcantly different when stratified by treatment branch and immunophenotype of ALL. Conclusion:The results showed that the G870A polymorphism of CCND1 was not associated with the risk of ALL in a southern Chinese population.