The present invention provides a rubber composition for a sidewall or a clinch having improved cut resistance, crack growth resistance and low fuel consumption for an automobile the present invention relates to a rubber composition for a side wall or a clinch comprising a rubber component containing: (a) 20 to 60% by weight of polybutadiene rubber containing 2.5 to 20% by weight of crystal 1,2-syndiotactic polybutadiene, (b) 5 to 40% by weight of a tin modified polybutadiene rubber polymerized by a lithium initiator, wherein the amount of tin atoms is 50 to 3000 ppm, the amount of vinyl bonds is 5 to 50% by weight and molecular weight distribution (mw/mn) is at most 2, and (c) 20 to 75% by weight of a rubber except for (a) and (b).