ObjectiveTo discuss the relationship between microalbuminuria (MAU) and antioxidant activity of plasma hyper density lipoprotein (HDL) in hypertensive patients, and investigate whether MAU could be a predictor of HDL antioxidant activity. MethodFrom December 2007 to March 2009, sixty consecutive primary hypertensive patients from the inpatient and outpatient departments of West China Hospital and Sichuan Electric Power Central Hospital were included in the study, and 30 healthy volunteers served as controls. MAU, plasma HDL and paraoxonase (PON1) activity were tested. ResultsPON1 activity was lower in hypertensive patients than the controls (P<0.05), and this degree of decline was positively related to MAU (P<0.05). ConclusionMAU reflects PON1 activity in hypertensive patients and can be a predictor to judge plasma HDL function in patients with hypertension.