In this study, proton conducting polymer electrolyte networks consisting of alginic acid (AA) and poly(1-vinylimidazole) (PVI) were prepared. The polymer networks were obtained by mixing AA and PVI with several stoichiometric ratios, x (with respect to monomers). Polymer networks were characterized by FT-IR spectroscopy and their compositions were investigated by elemental analysis (EA). Enzyme entrapped polymer networks (EEPN) were produced by immobilization of tyrosinase in the AA/PVI matrix during complexation. The maximum reaction rate (V-max) and Michaelis-Menten constant (K-m) were investigated for the immobilized tyrosinase. Also, the temperature and pH optimizations, operational stability and shelf life of enzyme immobilized in the polymer network were examined.