Rubber composition containing carbon black

A carbon black-containing rubber composition prepared using a starting rubber dissolved in an organic solvent or a starting rubber made into an aqueous emulsion, comprising a starting rubber A' having an average glass transition temperature TgA' of -120- to -15 DEG C first brought into contact with carbon black, then blended with a starting rubber B' having an average glass transition temperature TgB', which is at least 10 DEG C higher than TgA'.