The book includes introduction and 04 chapters: Chapter 1: International, regional and Vietnamese circumstances in the first half of the 19th century. Chapter 2: Diplomatic Relations of the Nguyen Dynasty with China in the first half of the 19th century. Chapter 3: Nguyen Dynasty's diplomatic relations with France in the first half of the 19th century. Chapter 4: Diplomatic relations of the Nguyen Dynasty with the countries of Siam, Chenla, Lan Xang Vientiane in the first half of the 19th century.