In the Vietnam South historiographical works in the 1950s - 1970s of the XX century, people paid special attention to Phan Khoang (1906 - 1971), because this author has spent a lot of effort to study the history of Cochinchina. Of course, he was not the only one that interested in exploring this area. There are many other authors in the Vietnam South before the year of 1975 such as Le Kim Ngan, Nguyen The Anh, Son Nam, Nguyen Hien Le ... have had the certain success in this area. However, A History of Vietnamese DANG TRONG (Cochinchina. 1558-1777) of the author Phan Khoang, right from the beginning was soon recorded by the readership. The problem is that this work is not only the most systematic and detailed restoration of the history of the Nguyen dynasty (1802 - 1945) in particular and the history of Dai Viet in the Le – Trinh dynasties’ division (1627 - 1673) in general, but this work is also based on a very large, immense, unique, rare documents & materials system. It is because writing about the history of Cochinchina not only touches on the history of the Vietnam South (Cochinchina) - the heroic and tear-sweaty history of the brave and liberated Vietnamese own people, but also touches on the history of the kingdoms of Champa and Chenla ... all these are the challenges to the history of that day and even today. It is very true to the suggestive name of the book, History of Vietnamese DANG TRONG (Cochinchina. 1558 – 1777): The Southward Expansion of the Vietnamese Nation is not only a history of a part of the national body, but also one of the most academic books of the 1960s on the basic issues & problems of the exploration of the land of the Vietnam South in almost recent 300 years. Especially, historian Phan Khoang has come to the conclusions on the nature of historical events (which are complex and overlapping) and these conclusions after nearly 50 years of real introduction into the process of “restoring the history of Dang Trong (Cochinchina)” still are referenced, suggested to historical awareness today. About the historic writing-style of Phan Khoang: it is a pen that is simple, elegant and very popular, even when it comes to the complex historical knowledge ... Thus, the history of more than 200 years that called History of Vietnamese DANG TRONG (Cochinchina) by him has a simple structure that is full of the events that do not hide the face of historical figures (from the character of the Nguyen family’s lords to the image of the common people - the so-called “the people’s lifestyle”); the mainstream historic pen is skillfully blended with the sharp style of the journalist, sometimes with a bit of “historic novel’s flavour”. This work of large caliber, with dense place & proper names in very censored Chinese scripts was first published in the year of 1969 of the last century by Khai Tri Publishing House.