A saddle-riding vehicle comprising: a steering handlebar; a vehicle frame structure; an upper bracket that is rotatably supported by the vehicle frame structure; and a handlebar mount structure to support the steering handlebar on the upper bracket, which mount structure comprises: a handlebar holder having a lower end portion supported by the upper bracket and also having an upper end portion clamping the handlebar, a holder shank being provided in a lower end of the handlebar holder, the holder shank having a tip end portion formed therein with a male thread; a holder shank throughhole defined in the upper bracket, through which the holder shank is inserted; a tubular elastic mount member inserted in the holder shank throughhole to suppress transmission of vibrations between the upper bracket and the handlebar holder, the holder shank being inserted in a holder shank insertion hole that is defined in an inner side of the elastic mount member; a rubber washer mounted on an outer periphery of the elastic mount member and disposed between the handlebar holder and the upper bracket; characterized in that a first and a second elastic member are interposed forwardly and rearwardly of the elastic mount member, respectively, at a location between the handlebar holder and the upper bracket; each of said first and second elastic members has a projection defined therein so as to extend upwardly or downwardly, and the projections are engaged in respective recesses formed in the handlebar holder or the upper bracket. a steering handlebar; a vehicle frame structure; an upper bracket that is rotatably supported by the vehicle frame structure; and a handlebar mount structure to support the steering handlebar on the upper bracket, which mount structure comprises: a handlebar holder having a lower end portion supported by the upper bracket and also having an upper end portion clamping the handlebar, a holder shank being provided in a lower end of the handlebar holder, the holder shank having a tip end portion formed therein with a male thread; a holder shank throughhole defined in the upper bracket, through which the holder shank is inserted; a tubular elastic mount member inserted in the holder shank throughhole to suppress transmission of vibrations between the upper bracket and the handlebar holder, the holder shank being inserted in a holder shank insertion hole that is defined in an inner side of the elastic mount member; a rubber washer mounted on an outer periphery of the elastic mount member and disposed between the handlebar holder and the upper bracket; characterized in that a first and a second elastic member are interposed forwardly and rearwardly of the elastic mount member, respectively, at a location between the handlebar holder and the upper bracket; each of said first and second elastic members has a projection defined therein so as to extend upwardly or downwardly, and the projections are engaged in respective recesses formed in the handlebar holder or the upper bracket. a handlebar holder having a lower end portion supported by the upper bracket and also having an upper end portion clamping the handlebar, a holder shank being provided in a lower end of the handlebar holder, the holder shank having a tip end portion formed therein with a male thread; a holder shank throughhole defined in the upper bracket, through which the holder shank is inserted; a tubular elastic mount member inserted in the holder shank throughhole to suppress transmission of vibrations between the upper bracket and the handlebar holder, the holder shank being inserted in a holder shank insertion hole that is defined in an inner side of the elastic mount member; a rubber washer mounted on an outer periphery of the elastic mount member and disposed between the handlebar holder and the upper bracket; characterized in that a first and a second elastic member are interposed forwardly and rearwardly of the elastic mount member, respectively, at a location between the handlebar holder and the upper bracket; each of said first and second elastic members has a projection defined therein so as to extend upwardly or downwardly, and the projections are engaged in respective recesses formed in the handlebar holder or the upper bracket.