We synthesized polyvinylalcohol cross-linked with a four functional porphin derivative by means of the copolymerization of tetra(vinylphenyl) porphin and vinylacetate, and the successive saponification. The number-average molecular weight of porphin-cross-linked polyvinylalcohol was 8 10 4 and the saponification degree was more than 99%. The cross-linkage formation was confirmed by the double detection technique of gel permeation chromatography. By observing the irreversible broadening of a photochemical hole under temperature cycles, we found that the covalent bonds between the porphin derivative and the host polymer, and the hydrogen bonds in the latter cooperatively suppress the structural changes in the vicinity of the former to reduce its spectral diffusion.