An image forming apparatus having excellent chargeability, sensitivity and light responsivity of an electrophotographic photoconductor and capable of forming images of high quality and high resolution at a high speed in various circumstances, is provided. An electrophotographic photoconductor having a photosensitive layer containing the enamine compound represented by the following general formula (1), for example, the enamine compound represented by the following structural formula (1-1) as a charge transportation substance is mounted to an image forming apparatus and the volume average particle size of the toner contained in a developer 50 housed in a developing device 33 is set to a size from 4 to 7 .mu.m. ##STR00001##