Providing the CAD system utilizing the network that does not need to prepare the graphic data beforehand and can provide the parametric graphic data that user expected promptly by simple order. The present invention of CAD system comprises server computer 1 and client computer 2 that are connected through the Internet 3. Server computer 1 is comprising Internet service interface program section 11, parts database administration program filing section 12, parts data list filing section 13, variable program file storing section 14, real data filing section 15, reformatting program filing section 16 and operation processing section 17.