In this paper, Korean epistemic expressions are classified based on the levels of certainty of the propositions they introduce. We already showed in Kawazoe at al. (2010b) that the following four tests are useful for classifying Japanese epistemic expressions: 1) the test of co-occurrence with ＂100%＂ expressions , 2) the test of co-occurrence with the context of prediction, 3) the test of occurrence in conjoined sentences where the same proposition is both affirmed and negated, and 4) the test of co-occurrence with ＂0%＂ expressions. This study has shown that those tests can also be made use of for the classification of Korean epistemic expressions.