This paper is to investigate so-called ECM constructions in Korean. It is generally assumed in the literature that the ECMed DP is a subject of a complement clause raised to the matrix landing site. But I will show that Korean ECMed DP is in fact the base-generated proleptic argument on grounds of evidence related to the long-distance relativization. Besides this conclusion, I will examine one alleged property of the Korean ECM constructions. It is quasi unanimously assumed that there exist restrictions on the category and the grammatical function of the embedded clause and on the embedded predicate such as the transitivity restriction. But we will see that such a restriction has no firm basis. I will also reveal one unknown property of these constructions; not only the subject but also the direct object, the indirect object and even the adjunct can be represented by a proleptic argument, c'est à dire can be ECMed.