As the first academic monograph in China dedicated to English word roots, the book is divided into three main parts and each part includes relevant exercises. The first part systematically discusses the basic theory of English word roots; the second part provides a detailed introduction to commonly-used English word roots and related derivatives; the third part offers a brief introduction to frequently-used word roots and their main derivatives. Emphasizing practicality and applicability, the book is better suited to the needs of the readers.