Provided is an automobile vibration-isolating rubber composition, characterized in that a rubber component comprises from 10 to 80% by weight of a polybutadiene rubber which is obtained through the polymerization using a rare-earth element catalyst and which has a cis content of 97% or more, and from 90 to 20% by weight of at least one type of a rubber selected from a natural rubber, a synthetic polyisoprene rubber and a polystyrene-butadiene copolymer rubber. The automobile vibration-isolating rubber obtained by vulcanizing the rubber composition of the present invention has a low dynamic factor compared to the conventional product, making it possible to decrease automobile passenger compartment noise caused by road noise.