The purpose of this study is to examine a Chinese teacher's decision-making and changes in beliefs in a designed, blended learning environment that explored the use of thinking tools (TTs) strategies in nurturing students' thinking skills. The study used a qualitative methodology of Cultural Psychology, Trajectory Equifinality Approach (TEA), to analyze data of a Chinese primary school teacher, Teacher C. Through the analysis, the authors found Teacher C went through five developmental stages. During these stages, the authors identified that (1) online support to address the teacher's problem was effective and multiple viewpoints at international workshops triggered the "Aha" experience. (2) Reflections on beliefs better facilitated exploring TTs strategies in a concrete context. (3) Social guidance, such as presenting Lesson Studies and support of researchers, guided good decision-making, but social directions, such as transferring of supportive administrators and opposition from senior teachers inhibited Teacher C from making certain choices. Based on these results, the authors offer two design principles, combining belief reflection activities with decision-making and paying attention to the interaction of social factors, to improve blended learning environments and to support Chinese teachers to explore TTs strategies in the future.