A color electrophotographic image forming apparatus which simplifies a configuration in which a rotary is rotated to change over respective developing devices to a development position to reduce the costs and save the space, and which simplifies the changeover operation to reduce an operating time. The image forming apparatus sequentially moves and changes over the respective developing devices supported by the rotary to the development position which faces a photosensitive drum by the rotation of the rotary. The rotary is rotated to move the developing devices. A cam is rotated integrally with the rotary, and thereby abutment portions of the cam are abutted against a regulating rotatable member so that the developing devices are spaced from a photosensitive drum. In a state in which the developing devices are abutted against the photosensitive drum, the cam is spaced from the regulating rotatable member by recesses of the cam.