To provide a hydraulic-motor drive circuit prevented from rolling back.

In a hydraulic motor drive circuit having a hydraulic-motor 5 which is communicated with a hydraulic pump 1 via a change-over valve 3, provided are a selection valve 9 which is connected to both ports of the hydraulic motor 5 and selects a high- and low-pressure; a pressure sensor 10 which is connected to the high pressure port of the selection valve 9; a check valve 11 and a pressure-reducing valve 12 which are connected from the low pressure port of the selection valve 9 to the hydraulic-motor 5; a rotation sensor 13 of the hydraulic motor 5; and a controller which sends a control signal to the pressure-reducing valve 12, receiving the outputs from the pressure sensor 10 and the rotation sensor 13.