The design support system regarding the present invention comprises a node data storage means that stores node data to generate functional models which present a group of function nodes which are functions divided from performance function of apparatus which is an objective to be designed and a group of part nodes which realize the functions in mutual relations, a functional model generating means that generates the functional models in reference to the node data storage means, a node designation receiving means that receives the designation of a node among the functional models, a node selection means that selects a node which has a mutual relation with nodes to which the designation are given, a display unit that displays the node selected by the node selection means.