Homogeneous polymer hybrids of silica gel and chitosan were obtained by utilizing the sol-gel reaction of tetramethoxysilane (TMOS). Chitosan was initially treated with phthalic anhydride to improve its solubility. This phthalated chitosan was further reacted with n-propyl isocyanate in DMF at 90 degrees C to introduce urethane groups as hydrogen bonding accepting groups in its side chain. The carbamated chitosan was mixed with TMOS in DMF in the presence of HCl as a catalyst for the sol-gel reaction of TMOS, and the resulting reaction mixture was heated at 90 degrees C for 200 h. The homogeneous and transparent composites were obtained when the ratio of the chitosan and TMOS was less than 1/4. The ET-IR measurement of the hybrid showed peaks for carbonyl groups shifting to lower wavenumber, which indicates the hydrogen bonding interaction between carbonyl groups of the organic polymer and silanol groups of the silica matrix. The homogeneity of the hybrid was found to be dependent on the initial content of TMOS and the acid catalyst. With the increase of TMOS or the acid catalyst contents, the homogeneity was improved. The homogeneity was estimated quantitatively by measuring the pore size of the charred chitosan hybrid by nitrogen porosimetry method, in which a sharp distribution at 1.7 nm was observed.