Abstract: Provided are a process for efficiently producing a rubber wet master batch in which a dispersibility of carbon black in the rubber is improved, in which a reinforcing property and an abrasion resistance of the rubber can be enhanced by using carbon black having a high surface activity, in which a yield of the carbon black in the wet master batch obtained is not reduced and in which a handling property of the carbon black is good as compared with master batches prepared by using a granulated and dried substance of carbon black prepared by a conventional wet method and non-granulated carbon black, a carbon black-containing rubber wet master batch obtained by the above process and a rubber composition and a tire prepared by using the master batch.