This paper categorizes currently available theories of focus into two major types: a ‘discourse structure approach’ (DSA) and a ‘sentence structure approach’ (DSA) and a ‘sentence structure approach’ (SSA). The former, DSA, is intended to refer to a type of approach that analyzes focus only in terms of discourse structure in which a focused sentence occurs. The Alternative semantics approach, which is the most widely available theory that analyzes focus in terms of sentence-internal structure. This study supports the SSA by revealing some empirical problems of the DSA that arise in analyzing two different kinds of focus, the A-accented focus and the B-accented focus (contrastive topic), and provides a brief sketch of a comprehensive analysis of focus and contrastive topic. (Sejong University)