The living anionic copolymerization of styrene with 1,2-bis(4'-ethenylphenyl)ethane (1) or p-divinylbenzene (PDVB) with sec-butyllithium in benzene was carried out. The copolymerizations of styrene with more than 20 mol % of 1 gave insoluble polymers in quantitative yields, whereas the yield showed the maximum (97%) for PDVB at 15 mol %. The content of unreacted double bonds of the network polymer formed by the copolymerization with PDVB was four times as large as that formed with 1. Gas chromatographic analyses of the copolymerization suggested close reactivities of the double bonds between styrene and 1, whereas a rapid consumption of PDVB compared with styrene was observed in their copolymerization. The r(1), r(2), and r(1)r(2) values for the copolymerization of styrene with 1 were determined to be 1.00, 1.09, and 1.09, respectively, which suggests that a more homogeneous network structure can be attained with 1. The living chain end of the produced living gel initiated the polymerization of tert-butyl methacrylate to give an insoluble block copolymer in a good yield. The hydrolysis of the ester group of the block copolymer led to an amphiphilic copolymer that exhibited a characteristic property of a hydrogel.