This essay introduces the Weight Formula as a new tool for exploring the balancing act between fundamental rights and for studying the constitutional dogmatics in Taiwan. Proposed by Robert Alexy, the Weight Formula comprises three factors: intensity of infringement, abstract weight and empirical certainty. Through a comprehensive discussion and examination of the Weight Formula and Interpretation No. 689 of Taiwan's Constitutional Court, the author intends not only to demonstrate the potential application and practical value of the Weight Formula, but also to point out a direction for future research.