Abstract: To investigate the biochemical characteristic differences of zona pellucida glycoproteins between oocytes and embryos are investigated through comparison between‚the zona pellucida components of unfertilized oocytes and that of 2-cell embryos were analyzed by SDS-PAGE‚and the analysis of the differences of O-linked sugars chains between unfertilized oocytes and2-cell embryos zona pellucida was carried out by HPLC．The results show that the samples of unfertilized oocytes and2-cell embryos have similar SDS-PAGE profiles‚but an additional band with the molecular mass between15000～30000was separated from the reduced sample of 2-cell embryos by SDS-PAGE．HPLC charts show that the sample of unfertilized oocytes had three O-linked monosaccharides with similar retained time values to those of 2-cell embryos‚while the O-linked oligosaccharides of the two samples were evidently different．It is concluded that the inactivation of sperm receptor of zona pellucida lies molecularly in the modification of its O-linked oligosaccharides‚but not in the change of O-linked monasaccharides． 

Key words: zona pellucida；O-linked sugar chain；glycoprotein；biochemical character