An improved video window control apparatus and a method thereof which are capable of generating a plurality of video windows on a television or a computer monitor, controlling the size and position thereof, and providing a video window overlap function and a picture-in-picture function. The apparatus includes a video window flow control means for controlling the size based on an input control of a video window and a position and overlap of the video windows based on a video output control and for outputting a video windows input control signal, a video output control signal, and a video selection signal, a plurality of video memory means for receiving a video signal outputted from an external video input and processing means in accordance with the video input control signal and for limitedly outputting the video signals in accordance with a video output control signal, and a video combining means for combining the video signals from the video memory into one video signal in accordance with the video selection signal and for outputting the video signal to an external video output means.