An image forming apparatus, comprising: a plurality of rotation members for bearing respective images; a plurality of D.C. motors for driving and rotating the plurality of rotation members, respectively; a phase detector for detecting phases of the plurality of rotation members; a phase adjusting device for carrying out an adjustment based on a difference of the detected phases of the plurality of rotation members so that phase differences among the plurality of rotation members have a predetermined relationship; and judgment means for judging whether or not it is necessary to adjust the phases of the plurality of rotation members based on the detection results obtained from the phase detector, characterized in that said phase adjusting device is adapted to carry out the adjustment during rotation of the D.C. motors before the D.C. motors stop after an image is formed, and is adapted to decelerate said each of said plurality of the D.C. motors according to a deceleration curve and simultaneously stop said each of said plurality of the D.C. motors after completion of the adjustment, wherein when the image forming apparatus carries out a printing operation, the judgment means is adapted to judge whether or not it is necessary to adjust the phases of the plurality of rotation members after the plurality of the D.C. motors are activated, and when the judgment means judges that it is necessary to adjust the phases of the plurality of rotation members, the phases of the plurality of rotation members are adjusted by the phase adjusting device, and when the judgment means judges that it is unnecessary to adjust the phases of the plurality of rotation members, a printing sequence is carried out. a plurality of rotation members for bearing respective images; a plurality of D.C. motors for driving and rotating the plurality of rotation members, respectively; a phase detector for detecting phases of the plurality of rotation members; a phase adjusting device for carrying out an adjustment based on a difference of the detected phases of the plurality of rotation members so that phase differences among the plurality of rotation members have a predetermined relationship; and judgment means for judging whether or not it is necessary to adjust the phases of the plurality of rotation members based on the detection results obtained from the phase detector, characterized in that said phase adjusting device is adapted to carry out the adjustment during rotation of the D.C. motors before the D.C. motors stop after an image is formed, and is adapted to decelerate said each of said plurality of the D.C. motors according to a deceleration curve and simultaneously stop said each of said plurality of the D.C. motors after completion of the adjustment, wherein when the image forming apparatus carries out a printing operation, the judgment means is adapted to judge whether or not it is necessary to adjust the phases of the plurality of rotation members after the plurality of the D.C. motors are activated, and when the judgment means judges that it is necessary to adjust the phases of the plurality of rotation members, the phases of the plurality of rotation members are adjusted by the phase adjusting device, and when the judgment means judges that it is unnecessary to adjust the phases of the plurality of rotation members, a printing sequence is carried out.