This book adopts a typical textbook approach and format for CGE beginners to learn and master the subject. It explains the economics theory behind the CGE models. The learning proceeds step by step from basic economic theories to advanced topics, from simple to more comprehensive CGE structures along with the corresponding computer programs. Each chapter reviews relevant economic theories; illustrates new material with examples, diagrams and exercises; and provides the mathematical models along with the GAMS computer programing codes. At the end of a chapter, exercises are assigned for practice and enhancing understanding.