This study explored the effect of using the inquiry-based science writing heuristic approach in class on metacognition and scientific creativity to enhance the ability of solving problems in science classrooms of elementary students. The results of this study were as follows. First, the science writing heuristic had a positive influence on the usage of metacognition necessary for learners to solve the problem with science. Second, the science writing heuristic contributed to the improvement of scientific creativity. In the process of inquiry-based approach, learners used scientific knowledge to come up with ideas and produce outcomes, therefore they could seek sanswers to scientific problems for themselves. Third, the science writing heuristic produced a positive awareness of science process skill because learners had more opportunities to think on their own than an existing passive class. In conclusion, this study found that the inquiry-based science writing heuristic approach encouraged learners to do inquiring activities in school classrooms, therefore contributing to the application of metacognition and the improvement of scientific creativity.