A structure for attaching a rear work machine to a tractor is provided. The tractor has a vehicle body which is provided with right and left rear work machine connection bodies, each having upper and lower connection portions. The rear work machine includes a base frame with an operators seat, which is provided with right and left attaching plates, each having upper and lower engagement portions. The rear work machine can be attached to the tractor by connecting the upper and lower engagement portions to the upper and lower connection portions, respectively. The attaching structure includes: a rear work machine attaching spacer disposed between the rear work machine connection body and the corresponding attaching plate, the rear work machine attaching spacer including: a fixing portion for fixing to the attaching plate and the upper and lower spacer engagement portions for removably connecting the upper and lower connection portions, respectively.
