There is provided a process for producing a both end-modified diene polymer rubber comprising the steps of: (1) polymerizing a conjugated diene monomer or a combination thereof with an aromatic vinyl monomer in the presence of a compound represented by the following formula (1) to produce an alkali metal end-carrying active polymer, and (2) reacting the alkali metal end-carrying active polymer with an amine compound, a ketone compound, an acrylamide compound, a heterocyclic compound or a silyl compound represented by specific formulas, respectively: R--(CH.sub.2).sub.n--X-M (1) wherein R is a functional group containing a substituent group-carrying nitrogen atom, X is a saturated or unsaturated hydrocarbon group comprising from 0 to 10 conjugated diene monomer units or aromatic vinyl monomer units, n is an integer of from 1 to 10, and M is an alkali metal.