Acrylic rubber (ACM), obtained by copolymerization of acrylic monomers, is known as a special rubber with excellent heat and oil resistance. Acrylic rubber is widely used in the automotive industry as sealing materials, hose materials, etc. This paper reports on the differences in physical properties depending on the monomer structure and cross-linking points of acrylic rubbers, and then on the concept and points to be considered when formulating compounding using acrylic rubber.