The swelling equilibria model of copolymer gel particles is proposed. It accounts for physical crosslinking as a result of hydrogen bonding. The modified Flory-Erman model is used to describe the elastic contribution to swelling. The model considers hydrogen bonding as a physical crosslinker. A free-energy-of-mixing term is represented using the extended Flory-Huggins theory. The interaction parameter chi in the model is a function of both composition and temperature. We then compare the proposed model with the swelling behaviors of copolymer gel particles. Our model offers fairly good agreement with the experimental data for given systems.