A general model of the gel/sol partition in the free-radical copolymerization of vinyl/divinyl monomers was developed, combining the statistical and kinetic modeling. It is emphasized that properties of the primary chains born at some conversion are effected by their partner primary chains. It was concluded that the present model had overcome some shortcomings in Flory’s and Tobita’s model and facilitated taking the influence of kinetics into account, and was shown to be rather general for the free-radical copolymerization of vinyl/divinyl monomers.