The crosslinked PVC[poly(vinylchloride)]s were used to measure the swelling equilibria for solbent(1)/solvent(2)/PVC(3) systems. Trichloroethylene, acetone and ethanol were chosen as the organic solvent for swelling the crosslinked PVCs. The measurement of swelling equilibria was carried out within 298.15K to 318.15K for the binary acetone(1)/PVC(2), trichloroethylene(1)/PVC(2), and ethanol(1)/PVC(2) systems, the ternary acetone(1)/trichloroethylene(2)/PVC(3), acetone(1)/ethanol(2)/PVC(3) systems. The swelling ratios of PVC were decreased after the increase of theirs for the acetone(1)/trichloroethylene(2)/PVC(3) systems and continuously increased for the acetone(1)/ethanol(2)/PVC(3) systems according to a increase of the content of acetone in their systems from the measured swelling data. Their results described that the acetone had a role of the good solvent and the trichloroethylene or the ethanol did the poor solvent. The theory of swelling equilibria was used to calculate swelling equilibria of acetone(1)/trichloroethylene(2)/PVC(3) and acetone(1)/ethanol(2)/PVC(3) systems. It consisted of a mixing energy term and an elastic deformation energy term that described the changes of the chemical potentials of each term, and the UNIFAC was chosen for a mixing energy term and each expression equation of the Flory, James and Guth, and Wall and White done for a elastic deformation term. The experimental swelling equilibria data for the acetone(1)/trichloroethylene(2)/PVC(3) systems and acetone(1)/ethanol(2)/PVC(3) systems were correlated to estimate the interaction parameters and the average molecular weights of branch chains between the main chains of cross-linked PVCs, and to calculate the volume fractions of PVCs in swelling equilibria with the swelling models. As a result, the experimental data were almost agreed with the calculated values within the experimental errors.