To provide an image forming system by which size reduction and simplification of a device can be achieved by loading a plurality of different kinds of binding members in one housing part, and by which the binding member of the kind specified by each job is properly mounted on a paper sheet bundle of the job.

The kinds and number of the binding members housed in the housing part are stored. The kind of the binding member specified by the job to be executed, and the kind of the binding member taken out from the housing part are compared. When they correspond to each other, binding processing is executed. When they do not correspond, the binding member of that kind is discharged, and until the kinds of the binding member correspond to each other, the comparison is repeated to carry out binding processing using the proper kind of binding member. When the binding members run short on the way or when the binding members exceed and are used in the next job in carrying out the binding processing on the one job, a warning is issued to make a user respond to it.