To provide a workpiece conveying system capable of positively conveying a workpiece and reducing conveying time.

The workpiece conveying system conveys the workpiece 16 to be machined from a workpiece supply region to a workpiece machining region of a machine tool and is provided with a workpiece holding device 20 for holding the workpiece 16. The workpiece holding device 20 is equipped with hand chuck jaws 36, a pusher member 47 to push the workpiece 16, and an air cylinder mechanism 38 to drive the pusher member 47. In connection with the air cylinder mechanism 38, a compressed air supply source 54 for supplying compressed air and a pressure control means such as an electropneumatic regulator 62 for controlling pressure of the compressed air are provided so that the pressure of the compressed air supplied to the air cylinder mechanism 38 is controlled by the pressure control means.