The purpose of this study is to develop the software that supports the externalization of ideas, reflection on thinking processes, and dialogues with oneself and with others during collaborative concept mapping. The characteristic functions of this software include the following: (1) playback: the software automatically saves the concept mapping process, and the learner can playback it at any time, even in the middle of the process; (2) improvement: the learner can return to any desired point in the concept mapping process by undoing it up to that point and improve the concept map; and (3) collaborative concept mapping: the learner can make a concept map in collaboration with others sharing the same screen on several computers linked to the same network. Twenty-four elementary school teachers were asked to evaluation this software in the questionnaire in terms of the usability of the software, convenience of the user interface, feasibility of collaborative concept mapping and playback of the collaborative concept mapping process, effectiveness of the functions, usability in lessons. Analysis of their responses demonstrated that many of the teachers highly evaluated the software in all aspects.