A systematic study of how different processes and crosslinking agents affect the crosslinked polymerization of poly(vinyl chloride) (PVC) to be used for plastisol application was carried out. Two processes, microsuspension (MS) and seeded polymerization (SP), and two crosslinking agents, diallyl phthalate (DAP) and 1,3-butanediol dimethacrylate (BDMA), were considered. Variations in degree of polymerization and gel content as functions of conversion, as well as the amount of crosslinking agent, was experimentally investigated for both processes and the results were precisely analyzed. We found that the microsuspension process is much better for crosslinked polymerization of PVC to be used for plastisol application; the seeded polymerization process was restricted by the transfer of crosslinking agents to the polymerization sites. Diallyl phthalate was proven to be a good crosslinking agent as generally known until now. Consequently, to perform crosslinked PVC polymerization in industry, the type of process should be taken into account and proper materials and steps should be set up.