This study was to find the perception of mathematical & scientific learning of North Korean students who lived in Korea. To understand their perception, three groups as the focus group for clinical interview, consisting of North Korean students, their teaches and their parents, were investigated through narrative description of qualitative method, North Korean students experienced the gap between what they had learned and what they learned in Korea, due to visiting the 3rd country before they came to Korea. So they were in need of well developed instructional instruments based on a precise diagnosis of language ability to help them get over their difficulties. Second, they have difficulties in math & science classes due to differences between curricular and to the differences between the ways of expression of terminologies used in two countries. They expressed that the group work in learning and a great deal of number of problems could be helpful for their needs. Third, the community-service center should be operated in a systematic way to compensate their lack of getting a private education. Fourth, they thought that the supplemental materials should provide some sources that might help them to get over the language barrier and difficulties from the differences, because they depended on them.