Creative teaching is becoming essential in sparking student’s interests and enhancing their performances. To improve teaching, teacher learning group is a good way to support teacher competence development. However, few studies have focused on how teachers make effective dialogue and generate creativity with others within a teacher learning group. Thus,we adapted Csikszentmihalyi’s systems model to reveal the way of the dialogue within a middle school science teaching group affected the developing process of group creativity. The mixed-method approach was adopted and data from video recordings and semi-structured interview during 2016-2017 were collected. We used constant comparative analysis to analyze the data. First, twenty-eight dialogue elements of group creativity in first order and nine in second order were identified. Next, a serial of Mann-Whitney U tests was conducted to examine the general and unique dialogue elements. After modifying by the interview data, the Interactional Group Creativity Model was constructed. In this model, group members would discuss fluently with the general dialogue elements. Furthermore, group creativity would be promoted with the unique dialogue elements, which are contained in five stages: 1. Goal-oriented context stage: Group members achieve shared understanding in group goals and directions; 2. Expanding stage: Group members demonstrate multiple teaching ideas proposing, alternative solution raising, and teaching resources sharing to broaden the group’s thinking and knowledge; 3. Understanding stage: Group members perform illustration seeking, explaining, and feedback to reinforce group’s knowledge basis in this stage; 4. Suspending stage: By distracting their attentions temporarily, group members consider more possibilities and developed appropriate ideas; 5. Information elaborating stage: Within the spiral circulation of the two stages, ideas and information are elaborated through contextualization and combination. It is noteworthy that the five stages are nonlinear but circles that might be generated within single or multiple stages. Group creativity developed and elaborated in the spiral circulation between the five stages. Based on the results, relevant empirical and theoretical research have been discussed, and the practical suggestions for scientific teacher groups have also been proposed.