Ideology is always an issue that plays an important role in the life of a society, and that ideology also greatly influences the process of ruling the country of dynasties in the history. Unlike previous dynasties, which lasted only a few decades, the Ly dynasty represents a flourishing period of feudalism lasting more than 200 years. A major event was that King Ly Thanh Tong changed the country name from Dai Co Viet to Dai Viet in 1054, ushering in a brilliant era in Vietnamese history. The ideology of “taking people as the root” of Vietnamese feudal dynasties highlights the unyielding and indomitable fighting spirit for the right to enjoy independence and freedom in the old land of Giao Chi and Cuu Chan, which later was Dai Viet and is now Vietnam. It also reflects the desire for people to live in peace and harmony. This articles focuses on studying the ideology of “taking people as the root” through the reign of kings of the Ly dynasty in Vietnam. From there, the article points out the achievements and limitations in the process of taking care of people, as well as historical lessons for the development of the country today.