We successfully modified the surface of PU (Polyurethane) foam (10 PPI) through atmospheric pressure plasma treatment and subsequent grafting of AAc (acrylic acid). The plasma treatment can generate large amount of peroxides on the surface of PU foam and the peroxide groups act as initiators for further grafting of AAc in the monomer solution. To introduce large amount of peroxides on the surface of PU foam, we studied the effect of plasma rf-power and treatment time on the maximum grafting of AAc. Through this study, we found that the optimum rf-power was 100 W and the optimum treatment time was 100 sec. On the other hand, we also studied the effect of graft reaction conditions such as temperature, monomer concentration and reaction time on the change of grafting degree (GD). The GD increased with temperature and increased with reaction time before it leveled off at 3 hr after reaction. At low concentration of AAc, the GD was very low but it showed the maximum at the monomer concentration between 60% and 70%. The surface of the modified PU foam was qualitatively and quantitatively analyzed with FT-IR and by weight measurement, respectively. We also observed the surface change before and after plasma induced graft co-polymerization through photo and SEM analysis. Finally, we confirmed the immobilization of Lysozyme through the electrophoresis analysis of proteins, which were recovered by the PU-g-PAAc foam from egg white.