This document provides lecture notes on health education. It contains definitions of key terms like health, public health, and health education. It discusses the historical development of health education and its aims and purposes. The principles of health education are also outlined, including definite aim, credibility, interest, participation, motivation, comprehension, reinforcement, learning by doing, known to unknown, role modeling, good human relations, leadership, feedback, successive experience, and group support. Principles related to changing health behaviors in clinical settings are also presented, such as educational diagnosis, the hierarchical principle, cumulative learning, and participation.