A lane-keep control system includes a traveling condition detector and a controller. The controller includes a steering intention detecting section that detects whether a driver has an intention to steer a vehicle, a first steering torque control section that controls, when the driver has no intention to steer the vehicle, a steering torque according to the traveling condition so that the vehicle keeps a predetermined position between lane markings of a lane, and a second steering torque control section that controls, when the driver has an intention to steer the vehicle, the steering torque according to the traveling condition so that a steering operation of the driver is readily reflected on steering of the vehicle. A lane-keep control method is also provided.