Music is one of ways to express affective activities of human beings. Therefore, there are many researches about music activities in the field of affective computing (Kansei Engineering). However, although most of those researches treat mainly the automatic generation of music using computer or the effects of music to human emotion or affective-cognitive, there are only few researches which deal with music composition as humans creative activities in the field of affective computing. It is desired to realize the system that can overcome drawbacks and support the collaborative music composition to exert specific creativity based on the human original affective activity. In this paper, we describe (1) conditions and method for supporting creative collaborative composing based on the analysis of human creativity (2) implementation of the system with supporting creative and collaborative composition, and (3) system evaluation and its result which shows availability of the system.