Abstract: In order to study the inhibition effect of Terminalia chebula Retz(TCR)on oxidative modification of the protein apoB100 contained in low-density lipoprotein(LDL),this paper studied the inhibition effect of the crude extract of TCR(CET)and the effective anti-oxidation part of TCR(EAFT)on the oxidative modification of the protein apoB100 contained in LDL by using qualitative and quantitative fluorescence techniques. The results showed that,CET could significantly(P<0.05)inhibit the decreasing of free amino activity of Lysine in apoB100,which showed a corresponding dose-effect relationship. The reactivity decreasing of free aminosin Lysine of apoB100 was remarkably inhibited by EAFT within the concentrations of 1.25~5.00 μg/mL(P<0.05). Trp fluorescence quenching was markedly inhibited by EAFT within the concentrations of 5~15 μg/mL(P<0.05). The generation of the total fluorescence products and lipofuscins were markedly inhibited by EAFT with the same concentrations. The inhibition effect of EAFT was intuitively showed on the three-dimensional fluorescence contour spectroscopy during LDL oxidation. This study would lay the foundation for further research and development of functional foods with antioxidant of LDL and anti-atherosclerosis.