The porous structure of copolymers obtained by suspension polymerization has been investigated. Three different copolymers were synthesized-styrene-divinyl-benzene, ethylene glycol dimethacrylate-divinylbenzene, and 1,4-phenylene dimethacrylate-divinylbenzene. All the copolymers were porous. As a pore-forming diluent, the mixture of toluene (good solvent) and n-dodecane (nonsolvent) was used. The influence of the composition of two-component diluent on the porous structure of the copolymers has been examined. Surface areas, pore volumes, pore size distributions, skeletal and apparent densities, and swellability coefficients were determined for the copolymers obtained in the presence of 0, 15, 50, 85, and 100% (v/v) toluene in the mixture with n-dodecane.