This study used the declassified documents and the process-tracing method to analyzed how Johnson administration's initial reaction and perception toward NorthKorea regarding the Pueblo incident had changed. Johnson administration's initial decision-making on the Pueblo incident had been dominated by the Cold War paradigm.The U.S.gave priority to the possibility of a plot between Soviet and North Korea and the diversion of the U.S. attention away from the Vietnam War. However, North Korea played hardball at closed sessions of the military armistice commissions, emphasizing the relation between the two nations,and propagandizing the outcome oft he Juche idea.Most importantly, the fact that the U.S. Department of State was involved directly in the negotiations resulted in the enhancement of North Korea's position as a nation. Moreover, following the visit of South Korea by Mr.Vance, the U.S. Senvoy, Johnson administration started the research on North Korea, which signaled the changes in the U.S. perception toward North Korea. This showed that the mini-detente in the Korean peninsula in 1970s was the result of the changed perception of the U.S. toward North Korea in the late Johnson administration.