Crosslinking of polyvinyl chloride (PVC) using a diamine such as ethylenediamine (EDA) as the crosslinking agent was studied. Studies were mostly made with unfilled compounds but the effects of fillers such as CaCO//3 and Ca(OH)//2 were also examined. The effects of variation of EDA content and the time of crosslinking at 170 degree C on the gel content (%), thermal (congo red) stability (min) and hot deformation (%) as well as curing characteristics using different proportions of EDA were also examined. Physical properties of the EDA crosslinked and those of uncrosslinked PVC were studied and compared. Activation energy of EDA-induced crosslinking was 15 kcal/mol (63 kJ/mol). Crosslinking mechanisms have been discussed.