Abstract: Two methods(couple by glutaraldehyde or EDC) were used to couple the SDE-ligands to the polyacrylamide(PAM) beads-supports for preparing adsorbents and the adsorbability of two adsorbents was determined in vitro.The results suggest that the adsorbents prepared by two methods mentioned above can selectively adsorb LDL.Ca~(2 ) can improve absorbent the efficacy of through cross-linking the phospholipid phosphate groups of LDL and the carboxyl groups of SDE ligands,and cross-linking the phosphate groups of neighboring phospholipids in LDL.The adsorbent whose ligands are immobilized on PAM beads by glutaraldehyde has better adsorbability than that of by EDC because there are higher density of COOH on surface of adsorbent prepared by the method of glutaraldehyde.