An opening and closing member control system includes a rotation sensing device, which outputs a pulse signal synchronously to a movement of a window glass, and a controller, which senses pinching of an object by an opening and closing member based on the pulse signal. The controller has leaning stored data Δωm based on the pulse signal. The controller computes a rotational speed difference Δω at a current position of the window glass based on the pulse signal while the window glass is driven in a closing direction. The controller computes a difference between the rotational speed difference Δω and leaning stored data Δωm in such a manner that the controller determines whether the pinching of the object based on a comparison between the difference and a pinching determining threshold value β.