The purpose of this study is to investigate the characteristics of scientific argumentation and its development in the process of mutual discussion activities by elementary school students in the 5th grade. The results of this study can be summarized as below: First, students used diversity argumentation components for solving the given argumentation theme, however, most students used the assertion or the basis of a simple expression of their own thoughts as a high ratio, and components of a one directional explanatory argumentation process rather than components of a mutual communicative argumentation process. Second, an asymmetric group showed a high-use ratio of communicative argumentation components and achieved argumentation activities harmoniously between a symmetric group and an asymmetric group in organization of groups for solving argumentation themes. It was found that students in the transitional period showed the highest rate of participation within the discussion process. Moreover, they also showed the highest rate of development of discussion skills whilst in the process of using scientific problems. In conclusion, this phenomenon is caused by highlighting the mutual action between the teacher and the student rather than placing an emphasis on the mutual action among students during field instructions.