Worldwide efforts to improve students’ learning of mathematics have turned educational researchers’ attention to some high-achieving education systems, especially those in East Asia including Chinese Mainland, Hong Kong, Japan, Singapore, South Korea and Taiwan. However, there is much less sharing and learning of educational policy and practices that goes beyond one or two such high-achieving education systems. At this time when educational changes and reforms for improving students’ learning of mathematics are also underway within these high-achieving education systems in East Asia, it becomes timely and important for the world to learn why and how relevant changes take place across these selected education systems. This book has put together a set of papers that individually presents issues on the changing mathematics curriculum and teacher education in the six high-achieving education systems in East Asia. Collectively, the book extends beyond what we can learn about exemplary practices in individual education systems in East Asia. It helps us develop a better understanding of the interplay between various measures for the pursuit of excellence in mathematics curriculum and teacher education on the one hand, and the different system contexts on the other. The intended readers of the book include education policy makers, curriculum developers, researchers, teachers, teacher educators, and anyone else interested in school mathematics curriculum and teacher education.