An implant abutment capable of stably adjusting vertical dimension of occlusion, the implant abutment comprising: an upper coupling portion that is an upper portion coupled to an artificial tooth; a lower coupling portion that is a lower portion coupled to a fixture; an exposed portion that is a portion exposed to the outside between the upper coupling portion and the lower coupling portion, and an adjustment groove that is formed on an outer circumferential surface of the upper coupling portion and inwardly recessed in the upper coupling portion, wherein the adjustment groove includes: two side surface; a bottom surface connecting lower ends of the two side surface; a base surface that is in contact with inner sides of the two side surface and positioned opposite to an entrance portion of the adjustment groove, and an imaginary surface positioned at the entrance portion of the adjustment groove, wherein among four edges of the side surface, a top edge thereof is formed to be shorter than a bottom edge thereof, and the base surface extends to be inclined toward the imaginary surface as the base surface goes in a direction from a surface of the upper coupling portion that faces the artificial tooth to a surface of the upper coupling portion that faces the fixture, characterized in that the base surface obliquely extends with an inclination angle of 2 to 7° with respect to an imaginary vertical line extending vertically from an edge of the base surface positioned close to the artificial tooth, and the imaginary surface obliquely extends with an inclination angle of 7 to 12° with respect to an imaginary vertical line extending vertically from an edge of the base surface positioned close to the artificial tooth, wherein the inclination angle of the imaginary surface is larger than that of the base surface. an upper coupling portion that is an upper portion coupled to an artificial tooth; a lower coupling portion that is a lower portion coupled to a fixture; an exposed portion that is a portion exposed to the outside between the upper coupling portion and the lower coupling portion, and an adjustment groove that is formed on an outer circumferential surface of the upper coupling portion and inwardly recessed in the upper coupling portion, wherein the adjustment groove includes: two side surface; a bottom surface connecting lower ends of the two side surface; a base surface that is in contact with inner sides of the two side surface and positioned opposite to an entrance portion of the adjustment groove, and an imaginary surface positioned at the entrance portion of the adjustment groove, wherein among four edges of the side surface, a top edge thereof is formed to be shorter than a bottom edge thereof, and the base surface extends to be inclined toward the imaginary surface as the base surface goes in a direction from a surface of the upper coupling portion that faces the artificial tooth to a surface of the upper coupling portion that faces the fixture, characterized in that the base surface obliquely extends with an inclination angle of 2 to 7° with respect to an imaginary vertical line extending vertically from an edge of the base surface positioned close to the artificial tooth, and the imaginary surface obliquely extends with an inclination angle of 7 to 12° with respect to an imaginary vertical line extending vertically from an edge of the base surface positioned close to the artificial tooth, wherein the inclination angle of the imaginary surface is larger than that of the base surface.