Abstract: Objective To study the expression of NAD（P）H oxidase subunits P^22phoxmRNA in blood phagocyte in patients with hypertension. Methods Subjects were divided into four groups based on family history of hypertension: group of hypertension and normotensives who had family history of hypertension （FH and FN group） and the group of hypertension and normotensives who had no family history of hypertension （NFH and N group）. The phagocytes in blood was acquired by density gradient centrifugation analysis. P^22phoxmRNA expression was determined by reverse transcription polymerase chain reaction. The activity of anti-oxygen species unit in serum was detected by colorimetric analysis.ResultsThe phagocyte NAD（P）H oxidase subunits P^22phoxmRNA expression was significantly increased in FH（6.60±0.59） and NFH（6.07±0.56） groups compared with FN（4.99±0.29） group and N（4.13±0.51） group. Differences of NADP（P）H oxidase subunit P^22phoxmRNA expression between FH vs NFH was significant（P＜0.01） as well as FN vs N group（P＜0.01）. The activity of anti-reactive oxygen species units was significantly decreased in hypertension group（FN:1151.55±118.3; N:1174.99±90.65;FH:777.59±43.69;NFH:797.91±44.48）. Conclusions The expression of NAD（P）H oxidase subunits P^22phoxmRNA is significantly increased in FH and NFH group compared with FN and N group. Impact of inheritance determinant on the expression of phagocyte NAD（P）H oxidase subunits P^22phoxmRNA is significant.