Since 1998, the English Immersion Approach, developed by the China-Canada-USA English Immersion project (CCUEI), has been trialed and promoted in over 50 elementary schools in China. Over those 20 years, this approach has advanced teacher development, improved student ability, and contributed to the overall development of schools, producing strong results both inside and outside China. This paper explores how this model integrates language learning and subject knowledge, with a focus on the rationale, curriculum mode, teaching principles and pathways to teacher development.