Choreography is one of the important parameters in dance performance. To make dance cool, it is necessary to design the cool choreography. However, beginners can hardly design choreography because they do not know how to judge the choreography good or bad. In this paper, we propose a system which automatically estimates the coolness of choreography for Lock dance and supports for the beginners to design choreography more sophisticated. To realize the proposed system, we focus on the suitability between the dynamics of dance move and music as a parameter of the coolness. We propose the estimation formula of the coolness based on the suitability, and evaluate it experimentally. As the result, it is revealed that the higher the suitability becomes, the higher the coolness becomes especially for the experienced participants feel on the experimented environment. Consequently, it is expected that the proposed system enables beginners to design cool choreography.