This study analyzes the distribution and interpretations of negative forms in Korean from functionalists` viewpoint of language, because they are heavily influenced by functions associated with constituents in a sentence/discourse. This study establishes a functional and discourse approach in the analysis of negation under the assumption that the interpretation of negation in Korean can be better explained by their functions in discourse. On the basis of this assumption, the distribution and interpretation of NEG-forms are examined in terms of transitivity. In addition, to examine why the two NEG-morphemes are so distributed, a transitivity theory is applied. In this theory, an can be regarded as an unmarked NEG-morpheme which negates predicates of either high or low transitivity, but mot must be regarded as a marked NEG-morpheme and is specialized to negate predicates of high transitivity only. The semantic interpretations of the NEG-morphemes an and mot then follow naturally as a consequence of derivation from the degree of transitivity each NEG-morpheme is associated with in the given predicate. In short, this study shows that the distribution and interpretation of NEG-forms cannot be explained in terms of purely syntactic form, but they can be explained better in terms of their functions in discourse.