Acrylic resin(ACR) was blended with a curing agent, hexamethoxymethylmela-mine(HMMM), in which blending ratio was 70:30. The curing behavior was examined using Rheovibron. Cross-linking reaction started at $170^{circ}C$ in 2 min of reaction and curing was completed in 10 min. It was found that the extent of cross-linking increased with the content of acetoacetoxyethyl methacrylate monomer in the ACR.