We have carried out educational reforms for more than twenty years in Taiwan, and have launched the 12-Year Basic Education since 2014. The experiences we have had indicate that teacher education reforms have always been the key issue to education reforms in Taiwan. This study aims to discuss the constitutional rationale of teacher education reforms by interpretative epistemology of the Constitution from an education basic rights perspective. Research findings are as follows: 1. The Teacher Education System built on Teacher Education Act does not seem to be sound enough; 2. The teacher education is related to education basic rights; 3. The Standards-based Teacher Education is viewed as the protection mechanism of organization and process for teacher education reforms in the coming decade; and 4. The Article 162 induced by the Constitutional Rule-by-law Rules is viewed as the constitutional rationale of teacher education reforms.