An object of the present invention is to provide a rubber composition for a sidewall having excellent conductivity, anti-spew cutting property and extrusion processability in good balance and assuring low production cost. The present invention provides a rubber composition for a sidewall comprising 2 to 15 parts by mass of a wet processed silica having a BET specific surface area of 70 to 250 m2/g and 40 to 62 parts by mass of a carbon black having a BET specific surface area of 37 to 125 m2/g based on 100 parts by mass of a diene rubber component, wherein the rubber composition does not contain a silane coupling agent, and has a volume resistivity of not more than 1×108 Ω·cm.