An image forming system, comprises: an image formation unit for forming an image on a paper; a first paper ejection unit for receiving the paper; a second paper ejection unit for receiving the paper as a sample paper in a state that the sample paper is visually checked when sample paper ejection is performed; a first control section for controlling a switching section to eject the sample paper by switching a paper sending destination from the first paper ejection unit to the second paper ejection unit at a time of the sample paper ejection; a second control section for controlling a display section to display thumbnail images; and wherein the first control section performs the sample paper ejection using the image for sample paper ejection selected by a selecting section for selecting the image for sample paper ejection from the thumbnail images displayed in the display section.