This paper aims to acoustically analyze the merger of back vowels in North Korean dialects which I believe, are here investigated for the first time since 1945. North Korean back vowels are distinctive from South Korean back vowels because they merge mainly on the back vowel space, while front vowels merge mainly in Seoul standard language and other South Korean dialects. In this paper the future of the vowel systems caused by the merger of the vowels in Korean dialects will also be investigated. North Korean dialects examined include dialects of the Pyungan, the Hamkyung, and the Hwanghae Provinces. North Korean back vowels are distinctive from South Korean back vowels because they merge mainly on the back vowel space, while front vowels merge mainly in Seoul standard language and other South Korean dialects.