An object of the present invention is to provide a novel solid reagent capable of solving the problems of conventional solid reagents based on resin beads.The present invention relates to a solid reagent comprising an organic polymer base in which a polymer side chain is introduced onto the backbone of the organic polymer base via graft polymerization and a reactive functional group is introduced onto the polymer side chain. The organic polymer base is preferably in the form of a fiber, a woven or nonwoven fabric consisting of an assembly of fibers, a porous membrane or a hollow fiber membrane. The graft polymerization is preferably a radiation-induced graft polymerization. Solid reagents according to the present invention can be used in various organic synthetic reactions.
