Introduction: "The book consists of 3 volumes introducing the basic information about the country and people of Laos and its people, about the basic characteristics of Laos through the fields of history - military, politics - economy and culture - society, compared with the characteristics of the country and people of Vietnam. Besides, the book also analyzes the past, current and prospects of connectivity in all areas of Vietnam-Laos relations. This will help to effectively implement the plan of cooperation between the two countries in the future, and also to realize Vietnam's foreign policy towards Laos." This book contains the following main contents: 1. The Communist Party of Vietnam and the Vietnam-Laos relationship in the struggle for national liberation. 2. the Laos situation after the Vientiane Agreement in 1973 and the establishment of the Lao People's Democratic Republic on 2 December 1975. 3. Ho Chi Minh City and the special relationship between Vietnam and Laos. 4. Some contents of economic cooperation between Vietnam and Laos in the renovation period (1986-2000) - advantages and disadvantages. 5. Overview of political, defense and security cooperation between Vietnam and Laos since 1986. 6. Comprehensive cooperation between Vietnam and Laos from 2001 - 2017 - Achievements and prospects.