The research is aimed at finding out how effective the use of authentic assessment based character education evaluation model is when conducted and carried out in Model Elementary School PAM, Makassar. Besides, this research particularly studies some basic characters such as accountability and responsibility, honesty, togetherness, and discipline especially in the fourth grade of any elementary school in the city of Makassar. The type of the research is Research and Development (R&D) referring to 10 (ten) model steps. However, the implementation, in reality, does not always go the way it is supposed to be as a result of limited time and ability as well as the budget availability. The ten steps have been modified into three simple steps, namely: (1) introductory and preliminary research, (2) model design, (3) and the development of the model. The concept used, developed, applied within the essence is what research and development (R &D) is really about. The result of data analysis showed that the evaluation model of character building based on authentic assessment using behaviour approach meets the criteria of effectivity.