The book introduces part of the results of archaeological excavations in 2008-2009 by the Institute of Archeology in Vietnam National Assembly House. After nearly 4 years of hard work, the Centre for Thang Long Royal Citadel Research under the Vietnam Academy of Social Sciences has completed the exhibit “The archaeological discoveries underground the National Assembly house”. The excavation has discovered 140 monuments and tens of thousands of archaeological relics of many periods. This is a very important discovery, vividly reflecting the long, continuous development history of the central citadel of Thang Long during 1300 years. At the same time, the National Assembly house construction area is an important part located in the southwestern part of the Thang Long Royal Citadel.