Objective:To investigate the relationship between the NAD (P)H oxidase p22phox C242T gene polymorphism and stroke. Methods:In this study,118 cases of cerebral hemorrhage,125 cases of cerebral infarction and 147 healthy controls were included,all cases are Han people in Shanghai region of China. Three groups had same baseline features of age,sexual proportion and BMI. Fasting glucose,and serum lipids were tested. The genotype and allele frequencies of the p22phox C242T polymorphism were determined by polymemse chain reaction－restriction fragment length polymorphism(PCR－RFLP) and gene sequencing technology. Results:The CT+TT genotype frequencies in the cecebral hemorrhage group,cerebral infarction group and control group were 9.3%,9.6% and 2.0%,respectively. T allele frequencies were 4.7%,5.2%,and 1.0%,respectively. The CT genotype and T allele frequency of the cerebral hemorrhage group and cerebral infarction group were significant higher than that of the control group (P < 0.05),one TT genotype was found in cerebral infarction group,and no TT genotype was found in cecebral hemorrhage group and control group,which was consistent with the results of gene sequencing. Binary logistic regression analysis was used to determine the correlation of CT genotype,cerebral hemorrhage (β = 1.712,OR = 5.537,95%CI:1.120~27.381,P = 0.036) and cerebral infarction(β = 1.432,OR = 4.187,95%CI:0.934~18.774,P = 0.061),respectively. Conclusion:These results suggest that the NAD(P)H oxidase p22phox C242T polymorphism was associated with cerebral hemorrhage and cerebral infarction,maybe serve as a risk factor. But compared to the traditional dangerous factors such as hypertension and alcohol,the effect of the C242T polymorphism on the cerebral infarction was not significant.