A display control system includes multiple image signal sources and image display devices. At the time of performing control for displaying picture signals from the multiple signal sources connected on respective sending lines to respective multiple areas on screens of image display devices, image display attributes information for each display area is stored in a per-area display attributes information storing unit, and an identification number of input pictures is obtained by an input signal identification signal obtaining unit. Based on the obtained identification signals, display selection information for appropriating the picture signals to the multiple display areas is created at a display signal selecting unit. The stored image display attributes information and the created display selection information are notified to the multiple signal sources connected to the respective sending lines.