To reduce a message in matching with a band width of a connection destination terminal by placing a 3-dimension virtual space common share device between a high band high speed network and a low band low speed network in order to attain inter-communication to avoid congestion of the network.

In the case of conducting communication in common share of a 3-dimension virtual space, multi-cast communication is conducted between user terminals 102 connecting to a broad band high speed network 101. A 3-dimension virtual space common share device 105 reduces a message in matching with a low band width for communication between user terminals 104 connecting to a low band low speed network 103 and in matching with a frame rate, the number of colors and resolution. Then the high quality 3-dimension virtual space is shared in common while utilizing a band width and high speed performance between the terminals 102 connecting to the network 101. The 3-dimension virtual space is shared in common with the quality corresponding to the network band width and the speed between the terminals 104 connecting to the network 103.