The optimal macroporous adsorption resin for enrichment and purification of gardenia yellow pigment (GYP) was determined by dynamic screening methods. The purification conditions were optimized and amplified. The properties of before and after GYP purification and the inhibition effects of these two kinds of GYP on low density lipoprotein（LDL)oxidation modification were compared. The results showed as follows:NKA macroporous resin was the most suitable resin for the enrichment and purification of GYP. The optimal purification conditions were that sample mass concentration was 0.72g/L, sample flow rate was 2BV/h(BV isbed volume), sample volume was 27BV, the solutions for washing impurities were 7 BV distilled water and 9BV 15% ethanol , followed by desorption with 3BV 80% ethanol at a elution rate of 2BV/h. Compared withGYP before purification (GYP-1), the color value of GYP after purification(GYP-2) increased by 5.14 times, The absorbance ratio of geniposide, chlorogenic acid and GYP (OD1 and OD2) decreased from 2.65 and 1.01 to 0.69 and 0.684 under the above optimal purification conditions, respectively. The enlarged process of the optimal purification conditions had stable efficiency and good effect. The different concentrations of GYP-1 had a significantly inhibitory activity on oxidation of LDL and the inhibitory effectpresented a good dose-effect relationship. Compared with GYP-1, the inhibition efficiencies of GYP-2 with the same concentration were significantly enhanced against the generation of conjugated dienes (CD)and malondialdehyde (MDA) (P<0.01). The effects on retardingspectral red shift, inhibiting the changes of LDL appearance colors and microstructures during oxidation were also stronger than those of GYP-1.