Following the end of the World War II, both Vietnam and Korean peninsula ware divided. Since the 1950s, South Korea (the Republic of Korea) and SouthVietnam (the Republic of Vietnam), North Korea (the Democratic People’s Republic of Korea) and North Vietnam (the Democratic Republic of Vietnam) started to establish official diplomatic relations. The Park Chung-Hee government from 1964 sent South Korean combating troops to Vietnam War battle fields and North Korea from this moment also started its assistance for Vietnam officially. This study examines and analyzes research trends in Vietnam so far on North and South Korea during the Vietnam War, which covers: ① South Korean participation in this war; ② North Korean assistance; and ➂ North-South Korean relationship. Firstly, the studies in Vietnam have formed discussion issues regarding the motivation of war participation, the fighting role on the battles and the results of sending South Korean troops to Vietnam. The views of Vietnamese academia are divided into “subjective” and “objective” motivations, that is to say South Korean government’s decision to dispatch troops to Vietnam was for national interest or followed the request by the US. The latter point of view is in fact in more accordance with the official standpoint of current Vietnamese government. It at last argues that the US was the one that took greater responsibility in sending South Korean combating troops to Vietnam. In reality, this point of view reflects the characteristics of the Vietnam War, at the same time reflects the current standpoint of Vietnam that the Vietnam War was indeed the “resistance war against the Americans.” On the fighting role and the importance of South Korean troops, changes of perception are happening now among Vietnamese scholars. There exists research trend that recognize the importance of South Korean troops in the battle fields based on their special fighting and operating capacity. Yet while mentioning the combating process of South Korean troops, these researches could not overlook the main leading-commanding role of the US. Studies of the results of sending troops mainly focuses on analyzing the interests that South Korean government received by participating in the war, surrounding military-economic, South Korea-South Vietnamese relations, US-South Korean relations, and politico-social aspects. Most of the studies mention the negative consequences of South Korean participation in the Vietnam War, such as strained North-South Korean relations, the anti-war movement within Korean society and all over the world which South Korean government had to face. Among the consequences that mentioned, the worst can be said the civilian massacres done by South Korean army during the Vietnam War. This has been seen leaving painful marks for Vietnam and the darkest chapters in the history of Vietnam-Korean relations. Secondly, this study analyzes the issue of assistance from North Korea during the Vietnam War, starting from the moment of formation of the solidarity community spirit between North Korea and North Vietnam. Through the books published since the 1950s, we are able to see North Vietnam’s interest in the Korean War which left lessons and experiences for Vietnam, at the same time the characteristic of North Korea-North Vietnam relationship at the moment – the Anti-American solidarity community spirit and Socialist solidarity community spirit. It was during the period of formation of the solidarity community spirit that North Korea paid attention to the Vietnam War and started to assist North Vietnam since the mid-1960s. In Vietnam in 2000 appeared researches on the assistance of North Korea and the dispatch of its air-force to North Vietnam. It can be argued that the announcement of North Korean assistance by Vietnamese government was thanks to the improvement of North Korea-North Vietnam relationship at the moment (follows Vietnam War’s end, the relationship between the two countries was worsen). In general, researches on the assistance by North Korea to Vietnam so far remain limited. Thus, the clarification of North Korea-China-North Vietnam relations with macro-level approach, as well as digging up material sources from the Vietnam side with micro-scope approach, is truly needed. Last but not least, to be brief, the research results in Vietnam on the North-South Korean relations during the Vietnam War affirm that the opposition and complexity of North-South Korean relations was stemmed from both inside and outside factors, especially the dependence on great powers. Among the outside factors that influenced the division of the Korean peninsula, current Vietnamese point of view sees the role of the US as crucial. In fact, with the perspective that the origin of the Vietnam War was due to US containment strategy in Asia, the division of Korean peninsula was seen in the same standpoint by Vietnamese scholars. Moreover, Vietnam - whose unification was achieved after a long resistance war - is insisting that the issue of division and unification of North-South Korea could only be achieved in a peaceful way.