A power seat slide device which adjusts a pair of sliders arranged at a predetermined interval by a driving force of a motor to adjust a position of a seat cushion in a front-rear direction in a vehicle seat, the pair of sliders each comprising: a lower rail fixed to a floor of the vehicle seat, with a longitudinal direction of the lower rail being along the front-rear direction of the seat cushion; an upper rail disposed to be movable along the longitudinal direction of the lower rail and supporting a cushion frame of the seat cushion; and a lock mechanism which locks the upper rail to the lower rail at an appropriate slide position, the device further comprising: a rack (21, 201, 2100) disposed along the longitudinal direction of the lower rail; and a pinion (22, 202, 2200) which is supported on the upper rail or the cushion frame, is meshed with the rack (21, 201, 2100), and rotates by the driving force of the motor being transmitted thereto, wherein, while the motor is energized, the motor is actuated in conjunction with a release operation of the lock mechanisms to rotate the pinion (22, 202, 2200) to cause front-rear movement of the upper rails along the lower rails, and wherein, while the motor is not energized, the front-rear movement of the upper rails along the lower rails is enabled by manual adjustment, characterized in that a control circuit formed of a parallel circuit of a rectifying element and a resistor is interposed between the motor and a power source which supplies a current to the motor, and wherein setting is made so that switching to rotate the motor in one direction causes the current to flow from the power source to the motor and the rectifying element of the parallel circuit in the order mentioned, and switching to rotate the motor in the other direction causes the current to flow from the power source to the resistor of the parallel circuit and the motor in the order mentioned. a lower rail fixed to a floor of the vehicle seat, with a longitudinal direction of the lower rail being along the front-rear direction of the seat cushion; an upper rail disposed to be movable along the longitudinal direction of the lower rail and supporting a cushion frame of the seat cushion; and a lock mechanism which locks the upper rail to the lower rail at an appropriate slide position, the device further comprising: a rack (21, 201, 2100) disposed along the longitudinal direction of the lower rail; and a pinion (22, 202, 2200) which is supported on the upper rail or the cushion frame, is meshed with the rack (21, 201, 2100), and rotates by the driving force of the motor being transmitted thereto, wherein, while the motor is energized, the motor is actuated in conjunction with a release operation of the lock mechanisms to rotate the pinion (22, 202, 2200) to cause front-rear movement of the upper rails along the lower rails, and wherein, while the motor is not energized, the front-rear movement of the upper rails along the lower rails is enabled by manual adjustment, characterized in that a control circuit formed of a parallel circuit of a rectifying element and a resistor is interposed between the motor and a power source which supplies a current to the motor, and wherein setting is made so that switching to rotate the motor in one direction causes the current to flow from the power source to the motor and the rectifying element of the parallel circuit in the order mentioned, and switching to rotate the motor in the other direction causes the current to flow from the power source to the resistor of the parallel circuit and the motor in the order mentioned. a rack (21, 201, 2100) disposed along the longitudinal direction of the lower rail; and a pinion (22, 202, 2200) which is supported on the upper rail or the cushion frame, is meshed with the rack (21, 201, 2100), and rotates by the driving force of the motor being transmitted thereto, wherein, while the motor is energized, the motor is actuated in conjunction with a release operation of the lock mechanisms to rotate the pinion (22, 202, 2200) to cause front-rear movement of the upper rails along the lower rails, and wherein, while the motor is not energized, the front-rear movement of the upper rails along the lower rails is enabled by manual adjustment, characterized in that a control circuit formed of a parallel circuit of a rectifying element and a resistor is interposed between the motor and a power source which supplies a current to the motor, and wherein setting is made so that switching to rotate the motor in one direction causes the current to flow from the power source to the motor and the rectifying element of the parallel circuit in the order mentioned, and switching to rotate the motor in the other direction causes the current to flow from the power source to the resistor of the parallel circuit and the motor in the order mentioned.