Big ideas are overarching principles that help students to build a holistic understanding of domain-specific knowledge and assimilate individual facts and theories. This study aims to design a standard-based integrated science curriculum framework based on Big ideas. The core contents were extracted by analysing the 2009 National science standards curriculum of primary and middle schools. Four Big ideas, ``diversity,`` ``structure,`` ``interaction,`` and ``change,`` were generated after the process of examination and categorization or core contents. The scientific facts. disciplinary concepts, and interdisciplinary concepts of every scientific domains included in each Big idea were represented as a knowledge pyramid. Essential questions guiding the direction of curriculum design were proposed on each Big idea. Based on the framework, teaching modules for ``structure`` were developed for grades 5--6.