This treatise analyzes Russian speakers’ pronunciation errors in learning Korean, aiming to clarify the phenomenon and reason of phonemes of their interlanguage. To begin with, it predicts the difficulties of pronouncing by means of contrast analysis and analyses Russian speakers’ practical pronunciation errors, there by examining diverse variations which appear in the intermediate stage, that is, the patterns of interlanguage. This treatise considers the reason of interlanguage based on analysis and skills. The individual phoneme is much interfered from the mother tongue. (Seoul Women’s University)