A post-processing apparatus includes a compile tray that contains a recording sheet and has a sheet end position determination portion contacting with and determine a position of an end edge of the contained recording sheet, a first sheet end alignment member that carries the recording sheet to the sheet end position determination portion and aligns the end edge, a second sheet end alignment member that moves between the sheet carrying position and a standby position, wherein the sheet carrying position is where the second sheet end alignment member contacts with the recording sheet to carry the recording sheet to a side of the first sheet end alignment member, and the standby position is separated from the recording sheet, and a second sheet end alignment member control unit that moves the second sheet end alignment member between the sheet carrying position and the standby position and changes a carrying position sustaining time to sustain the second end alignment member at the sheet carrying position according to a sheet number of the recording sheets.