Blending of ethylene–methyl acrylate (EMA) copolymer and polydimethyl siloxane (PDMS) rubber led to miscibility of the two components under the processing conditions of 180°C and 100 rpm rotor speed, and the miscibility was assumed to be due to reaction between EMA and PDMS rubber. A plausible mechanism has been suggested. The mechanism has been confirmed by infrared and solid-state MAS nuclear magnetic resonance spectroscopy, which show a reduction in the vinyl group concentration of PDMS rubber and an increase in the‒CH2‒bridge concentration of EMA in the vicinity of the α-carbon atom in the blend.