At the time of the Korean war, the issue of POW's negotiations on the surface was ‘Voluntary Repatriation’: The actual number and percentage of prisoners repatriated was a substantial issue of the negotiations which was not revealed. Since the both sides exchanged the lists of prisoners, the primary issue in the negotiations was notable difference in the number of prisoners and North Korea's unilateral prisoner treatment. In response to the preceding facts, the United Nations Command claimed ‘Voluntary Repatriation’, and proceeded to the examination and classification of prisoners by itself reducing the number of prisoners to be repatriated as much as possible. UNC's POW treatment was characterized with ‘release’ or ‘repatriation’. The release of Civilian Internees of primary and secondary enforcement, Rhee's ‘6.18 Anti-communist prisoners freed’(escape), and the process of final release after the NNRC's ‘Persuasion’ was ‘Release.’ On the other hand, the exchange of wounded prisoners and prisoners wished to repatriate was ‘Repatriation’, that the both sides agreed to come. The way to deal with the prisoners from the both sides started differently, but the result was the same. The process that North Korea dealt with prisoner was unilateral at first and UNC follow after was the 'Release', and that was agreed by both sides was the 'Repatriation'. The ‘Repatriation’ was done when the both sides agreed. Failing to return the ROK's prisoners issue is war heritage due to the processing the prisoner unilateral by both sides.