The distribution of adverbs is fairly restricted, even though there remain some cases of the free distribution (Jackendoff(1972), Travis(1988), and Cinque(1999)). The purpose of this paper is to explain the distributional restriction and freedom of adverbs. We proposed that the distributional facts of adverbs, including Class V and VI adverbs, which have not been given a deep research since Jackendoff(1972), can be well-captured by a local condition on the adverb licensing based on the Phase Theory (Chomsky(1998, 1999)) and the adjunct/ complement distintion. We critically reviewed the two different types of approaches to the adverb distribution in comparison to our analysis: adverbs as heads (Travis(1984)) and adverbs as specs (Laenzlinger (1993), Rijkhoek (1994), Alexiadou (1997), Cinque(1995, 1999)).