The purpose of this study was to find out how portfolio evaluation, when applied to Korean writing class of the 4th grade elementary students, could affect the self-regulated learning ability including metacognition, behavioral strategies, and motivation The verified results through this study were summarized as follows. First, the groups who were applied the portfolio evaluation showed higher improvement in self-regulated learning ability than the other group who were evaluated by traditional way. Second, portfolio evaluation affected positively to the improvement of metacognition, behavioral strategies, and motivation. Third, presenting performance standards when applying portfolio evaluation affected to elevate the students' metacognition. Education is ultimately forming the base of self-regulated person to develop as a whole man through out the life. Therefore, portfolio evaluation is very useful and effective way to regulate one's cognitive, emotional, and behavioral domain which control self-functioning.