Research of hydrogel and responsive polymer has been developed rapidly. Advance technologies have made it easier to make a hydrogel based on responsive polymers. One area that has been investigated is the pH sensitivity of polymers and hydrogels. In this research, the synthesis and optimization of pH-responsive P(NMA-co-AM) hydrogels by free radical polymerization using methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as initiator, were conducted. The purpose of this research is to investigate the best contexture of P(NMA-co-AM) hydrogels which had the best swelling ratio by varying the monomer ratio and the concentration of crosslinkers. The results of this study showed that the swelling ratio of homopolymer and copolymer hydrogels increased by the increasing number of acrylamide monomer added. The optimum swelling of P(NMA-co-AM) hydrogel was achieved on monomer composition NMA:AM 40:60 with MBA concentration of 4 % and the pH with the highest swelling ratio of P(NMA-co-AM) hydrogels was achieved in pH ranging 5-7.