Abstract: Platinum nanoparticle was prepared by using sodium borohydride as reductant. Sodium carboxylmethyl cellulose （CMC）, hydroxypropyl cellulose （HPC）, and polyacrylic acid （PAA） were used as protective agent to improve the stability of the platinum colloids. Glucose biosensors were formed with glucose oxidase （GOD） immobilized in composite immobilization membrane matrix, which was composed of platinum nanoparticles and polyvinyl butyral （PVB） by a sol-gel method. It shows that nanoparticles can significantly enhance the catalytic activity of the immobilization enzyme. The current response for the enzyme electrode containing Pt sol increases from 318nA· cm^-2 to 13657nA· cm^-2 in the solution of 10mmol/L β-D glucose. It proves the function of nanoparticles in immobilization of enzyme. The catalysis of enzyme improved by nanoparticles is discussed. The influence of different conditions is analyzed.