Abstract
This review describes the characterization of network polymers by ESR, mainly focusing on the following two points : (1) Generation of the inhomogeneity of network structure, which was discussed by pursuing the accumulation and spectral change of growing polymer radical and pendant radical generated in the radical crosslinking polymerization of multivinyl compounds. (2) Evaluation of the micro-Brownian motion of polymer and generation of the inhomogeneization of the resulting network structure with the progress of crosslinking, which were pursued by using spin probes and/or labels.