In order to provide a rubber composition in which dispersibility of silica is improved and in which a viscosity of an unvulcanized rubber is lowered and a heat build-up improving effect of a vulcanized rubber is well exerted, and a tire prepared by using the rubber composition, the rubber composition is endowed with a constitution in which 100 parts by mass of at least one rubber component selected from natural rubber and/or diene base synthetic rubbers are compounded with 55 to 200 parts by mass of silica and 0.5 to 15 parts by mass of at least one of alkanolamines represented by the following Formula (I): [in Formula (I), R1 represents an alkyl group or an alkenyl group having 1 to 24 carbon atoms, and the above alkyl group and alkenyl group may be any of a linear group, a branched group and a cyclic group; m and n represent an average addition molar number, and m and n are numerical values which represent m+n=1 to 20].