A fusing unit and an image forming apparatus to form an image on a recording medium including a fusing unit are provided. The image forming apparatus includes a heating member having a surface divided into a plurality of heating regions and heating the recording medium, and a pressurizing member to apply pressure to the recording medium, the fusing unit fusing the image to the recording medium by applying heat and pressure to the recording medium, a driving unit to supply rotational force to the pressurizing member, and a power supply to supply power to the heating member and the driving unit, wherein the heating regions have different heating values per unit area. The image forming apparatus prevents overheating of a paper-contact heating region without idling the fusing unit in order to radiate heat accumulated in the paper-contact heating region.