Objective To evaluate the associations of oral contraceptives (OC) exposure,angiotensin-converting enzyme(ACE) gene polymorphism and their joint actions with the risk of stroke in Chinese women.Methods A case-control study,based on a set cohort,was carried out.Incident cases of stroke identified between July 1 1997 and June 30 2009 were enrolled.One hospital control and healthy community control were matched on region and age ( ± 3 years).A total of 453women with stroke and 919 controls were recruited.I/D genepolymorphism was detected by polymerase chain reaction (PCR) and amplification fragment length polymorphism (AFLP),A-240T polymorphism were detected by TagMan.Results ( 1 ) The risk of stroke gradually increased with the cumulative time of OC being used in women (P＜0.0001).Compared with non-users,the risk of stroke significantly increased among those with cumulative time of using OC longer than 20 years (adjusted OR was 2.07,with 95％ CI as 1.30-3.29).(2) ID/DD genotype of I/D locus indicated significantly an increased risk of hemorrhagic stroke (adjusted OR,2.37; 95％CI,1.46-3.84).(3)Women with ID/DD genotype of I/D locus or with TA/TT genotype of A-240T locus and using OC could significantly increase the risk of hemorrhagic stroke (adjusted OR was 4.59; with 95％ CI as 2.21-9.51 and OR was 2.50; with 95％CI as 1.42-4.38).(4) Data from multivariate analyses showed that both OC and ID/DD genotypes were important risk factors for hemorrhagic stroke.Conclusion ID/DD and TA/TT genotypes of ACE gene,OC and their joint action might increase the risk of stroke,especially on hemorrhagic stroke in Chinese women.