The purpose of this study was to investigate the effect of social interaction on metacognition, learning motive and academic achievement in elementary science learning. The science lessons emphasizing social interactions that is applied to this study was comprised of 5 stages, 'introduction', 'inquiry activity', 'small group emergent activity', 'large group emergent activity', 'conclusion and assessment'. The results of this study were as follows: First, applying the learning model emphasizing social interaction to the experimental group led to a significant difference between the result of the pre- and post-test, regarding metacognition, especifically those of declarative knowledge. And meaningful difference was drawn from the results of all elements in the lower category of regulation of cognition between the experimental and comparison group. Second, a significant difference was found between the pre- and post-test regarding learning motive, especially those of attention, relation, and self-confidence. Third, after applying the learning model emphasizing social interaction to the science classes of the experimental group, students' academic achievement improved significantly in the post-test, compared to the results of pre-test.