This book draws on genetic theory to explore the microstructure of lexical meaning, the operating mechanism of the lexical semantic system and its formal representation, and methods for large-scale lexical computing resource construction. At the theoretical level, the basic framework of lexical semantic gene theory is proposed and elaborated. In this context, a lexical semantic gene is a basic structural unit of lexical meaning that controls a semantic feature of a word and can be inherited and recombined to construct a new word. Lexical meaning has multiple dimensions, and each dimension is regarded as a semantic feature composed of several lexical semantic genes according to certain semantic relations. The generation of new words is the result of the inheritance, reorganization, and mutation of lexical semantic genes. Drawing on this basis, the book subsequently explores the techniques of lexical semantic gene extraction and formalized description of lexical semantic genetic structure at the level of engineering technology. Bearing in mind the dual needs of formalized representation of semantic computation on the one hand and traditional language teaching, research, and lexicography on the other, the book employs language fact analysis to define strategies, methods, and operational procedures for a lexical semantic gene depiction meta-language system, lexical semantic genetic structure analysis, and lexical semantic gene extraction. At the application level, the computational and traditional applications of the lexical semantic gene database are discussed.