The rheological behavior and crosslinking kinetics of model filled rubber compounds during curing were investigated. The effect of chemical composition of monodisperse size particles, prepared by emulsifier-free emulsion polymerization, on dynamic moduli and gelation time of the filled compounds was studied. All filled systems showed much shorter gelation. times than:the pure matrix in the order PSVP < PS < PMMA < Pure Matrix. The dynamic moduli during curing increased with increasing interactions between particles and matrix. Physical crosslinking, due to either particle clustering or a network of filler particles with an adsorbed polymer layer, made a significant contribution to the overall crosslink density and the gelation. of rubber compounds. As a result, the dynamic mechanical properties and curing kinetics of the rubber compounds varied with the chemical nature of the filler particles.