The present invention provides a rubber composition for obtaining golf ball having good processability, excellent rebound characteristics and excellent durability. The present invention relates to a rubber composition for golf ball comprising a base rubber, a co-crosslinking agent, an organic peroxide, a filler and a processing aid, wherein the base rubber comprises a polybutadiene (a) containing a cis-1,4 bond of not less than 80% and synthesized using lanthanide-containing catalyst, the organic peroxide comprises an organic peroxide having 10 hours half-life period temperature of 80 to 100.degree. C., and the processing aid is fatty acid ester, fatty acid salt or the mixture thereof.