We report our ongoing challenge to establish knowledge building curriculum for elementary school children in their science lessons. We base our curriculum on Japanese Elementary Science Activity Structure (JESAS) (Linn et al., 2000), and further elaborate it by 12 determinants of knowledge building community (Scardamalia, 2002). Our approach to constructing the curriculum has taken several steps of design studies in collaboration among teachers, learning scientists, and subject matter experts. The first step was design studies by which we attempted to figure out what were missing in JESAS to grow as the knowledge building practice (Oshima et al., in press). What we report here is the next step of design studies where we implemented particular design elements for the purpose of transforming existing activity structures into the knowledge building practice. Two elementary science teachers conducted their lessons on genetically modified foods and combustion, respectively, based on our reflection upon the first design studies. Examples of knowledge building activities that students were engaged in are described with explanations on what design elements were implemented. Further, our findings are discussed for articulating lessons that cover 12 determinants in knowledge building curriculum.