In lane keep control apparatus and method for an automotive vehicle, a traveling state of the vehicle is detected, a determination is made on whether the vehicle has a tendency of a deviation from the traveling traffic lane according to the detected traveling state, a deviation avoidance control is executed for the vehicle in a direction to avoid the deviation according to the traveling state, steering angles before and after a start of the deviation avoidance control are detected, and a controlled variable of the deviation avoidance control is detected on the basis of a deviation between a steering angle before the start of deviation avoidance control and that after the start of deviation avoidance control when a determination is made that the vehicle has the tendency of the deviation.