Soft power plays an increasingly important role in national development and competition. "The Theory of National Soft Power" defines the concepts and connotations of hard power, soft power, and smart power, and analyzes the interrelationship between the three; summarizes the international experience in national soft power construction, and analyzes the experience of soft power construction in the United States, Russia and other countries; discusses the practices and problems of my country's soft power construction, and ideas for improving my country's soft power; and proposes four major principles to adhere to in improving national soft power: national interest strategy, national marketing, international responsibility, and national IQ.