This handbook is a culmination of the authors’ three-year research and development effort into blended learning for in-service Chinese Language (CL) teachers’ professional development. The primary audience of this handbook is teacher educators who would like to learn about blended learning as an approach for in-service teachers’ courses. Chapter One introduces the definition and theoretical underpinnings of blended learning. Chapter Two covers the model of blended learning the authors used, its design principles, and the relevant strategies. Chapter Three shares the findings on how blended learning had impacted some of the teacher-participants. Chapter Four, written by three highly experienced CL Master Teachers, captures their individual first-hand reflections and experiences of blended learning for teachers’ professional development. Finally, Chapter Five provides a brief conclusion to the handbook.