Lattice-valued logic aims at establishing the logical foundation for uncertain information processing routinely performed by humans and artificial intelligence systems. In this textbook, a general introduction to lattice-valued logic is provided for the first time. It systematically summarizes research from the basic notions to recent results on lattice implication algebras, lattice-valued logic systems based on lattice implication algebras, and the corresponding reasoning theories and methods. The book offers the suitable theoretical logical background of lattice-valued logic systems and supports newly designed intelligent uncertain information processing systems as well as a wide spectrum of intelligent learning tasks.