Objective To investigate the oxidation of high-density lipoproteins(HDL) in vitro and protective effects of probucol. Methods Human plasma lipoproteins were separated by one-step ultracentrifugation with a simple density-gradient. The in vitro oxidation of HDL was mediate by CuSO4

the oxidative effect of Cu2+ and the antioxidation effect of probucol were assayed simultaneously by thiobarbituric acid reactive substances (TBARS). Results (1) Cu2+ could effectively mediated the oxidation of HDL in vitro

which was both dose-dependent and time-dependent with Cu2+ within definite ranges.(2) The oxidation of HDL in vitro could be inhibited by probucol

and 5μmol/L probucol was effective obviously. Conclusion HDL is susceptible to oxidation and probucol can inhibit the Cu2+ mediated oxidation of HDL in vitro.