The gelatin and fusion processes of polyvinylchloride(PVC) plastisol were characterized on the thermal and dynamic rheological bases by incorporating a homologous series of dialkyl phtha]ates such as dimethyl(DMP), di-isohexy(DHP), di-2-ethylhexyl(DOP), and isooctylphthalates(DIOP) into PVC. The solvent power of a plasticizer played the most significant role in both processes. A plasticizer with a strong solvent power, DMP, penetrated into some of the PVC particles and swelled or even dissolved them at room temperature. On the other hand, plasticizers with weak solvent power such as DOP, and DHP seemed to be absorbed only into the interstitial pores of the agglomerated PVC particles below T of PVC. However, at the temperatures exceeding Tg, all the plasticizers penetrated into the PVC particles and little pure PVC amorphous phase was left.