To easily realize the sharing of a mouse among plural hosts.

The programs of hosts 1 to 3 connected by a LAN are respectively provided with mouse monitoring processes C1 to C3 and extension mouse drivers B1 to B3, mouse transition areas a1 to a3 are prepared in the screen edge part by the bitmap memory of each host, and a mouse is connected to the extension mouse drivers B1 to B3 through a distributor. The mouse monitoring process C1 is started (1) by moving a mouse cursor to the area a1, erases the mouse cursor from a CRT1 (2), also instructs the driver B1 to perform mouse lock (3) and issues transition notification to the mouse monitoring process C2 of the host 2 (4). The mouse monitoring process C2 of the host 2 is started according to the notification, instructs the driver B2 to release the mouse lock (5), resumes communication with the mouse and makes the mouse cursor appear (6). The transition from the host 2 to the host 3 is performed in the same manner ((7) to (12)).