An image forming system comprising: a plurality of image forming apparatuses (100, 200) provided in a series so that each of the plurality of image forming apparatuses form an image on a sheet of paper, wherein the plurality of image forming apparatuses each include: an image forming section (121, 221) which forms an image on the paper; and a control section (181, 281) which, when a predetermined adjustment condition occurs in any of the plurality of image forming apparatus, stops an image forming operation by the image forming section (121, 221) in the image forming apparatus in which the predetermined adjustment condition occurred, performs a predetermined adjustment, resumes the image forming operation by the image forming section (121, 221) in the image forming apparatus in which the predetermined adjustment condition occurred after the adjustment is complete, and performs a notification that the adjustment is performed to the other image forming apparatus of the plurality of image forming apparatuses when the adjustment is performed, and when there is a notification that the adjustment is performed from the other image forming apparatus of the plurality of image forming apparatuses, the control section (181, 281) either: stops the driving of the image forming section (121, 221) and puts the image forming section in a driving stopped state while the adjustment is performed in the other image forming apparatus, or the control section (181, 281) of the plurality of image forming apparatuses (100, 200) each specify time necessary for the adjustment when there is the notification that the adjustment is performed from the other image forming apparatus, and when the specified time is less than a predetermined judgment time, the driving of the image forming section (121, 221) is not stopped and the image forming section is on standby in a ready state until the adjustment is complete. a plurality of image forming apparatuses (100, 200) provided in a series so that each of the plurality of image forming apparatuses form an image on a sheet of paper, wherein the plurality of image forming apparatuses each include: an image forming section (121, 221) which forms an image on the paper; and a control section (181, 281) which, when a predetermined adjustment condition occurs in any of the plurality of image forming apparatus, an image forming section (121, 221) which forms an image on the paper; and a control section (181, 281) which, when a predetermined adjustment condition occurs in any of the plurality of image forming apparatus, stops an image forming operation by the image forming section (121, 221) in the image forming apparatus in which the predetermined adjustment condition occurred, performs a predetermined adjustment, resumes the image forming operation by the image forming section (121, 221) in the image forming apparatus in which the predetermined adjustment condition occurred after the adjustment is complete, and performs a notification that the adjustment is performed to the other image forming apparatus of the plurality of image forming apparatuses when the adjustment is performed, and when there is a notification that the adjustment is performed from the other image forming apparatus of the plurality of image forming apparatuses, the control section (181, 281) either: stops the driving of the image forming section (121, 221) and puts the image forming section in a driving stopped state while the adjustment is performed in the other image forming apparatus, or the control section (181, 281) of the plurality of image forming apparatuses (100, 200) each specify time necessary for the adjustment when there is the notification that the adjustment is performed from the other image forming apparatus, and when the specified time is less than a predetermined judgment time, the driving of the image forming section (121, 221) is not stopped and the image forming section is on standby in a ready state until the adjustment is complete.