Confucianism was born twenty-five centuries and has lasted for so long over a wide area including China, Korea, Japan and Vietnam. That is one thing that needs to explain why. Explaining this would certainly be difficult to convince if the mere theory of its richness and depth. It must have the conditions to be born and exist in the socio-economic base of East Asia, first of all in China, where it was born. The conditions for its birth only exist in China, but the conditions for its long-term survival are in all three countries of Korea, Japan and Vietnam and must be similar to those in China, at least about culture generally. In the history of Vietnam, since independence, the feudal dynasties of Vietnam have begun to use Confucianism was an effective way to govern and manage society. It is not surprising that the laws enacted by the feudal dynasties of Vietnam all have Confucianism imprints. Those were ancient laws code; the most typical was built and issued in Vietnamese history (from the 11th century to the 19th century). Based on the study of ancient bibliographies, in consultation with researchers and colleagues, this study provides insights and assessments of the Confucian imprints in the Hoang Viet Luat Le (called the Gia Long law) of Nguyen Dynasties of Vietnam; It also raises some controversial issues about the position and role of Confucianism in the history of Nguyen Dynasty Vietnam so that colleagues and researchers continue to study and debate.