In this paper, the relation between pause characteristics and local phrase dependency structure is examined in about 28,000 accent phrase boundaries in sentence speech data from ten professional broadcasters. The distribution of pause length showed the existence of two main types (long and short). The distribution of pause lengths normalized by tempo showed the two peaks more clearly at one and three mora-lengths. The linguistic analysis of these pause boundaries showed: 1) long pauses, inserted by many speakers, occurred predominantly at right-branching phrase boundaries, phrase boundaries with punctuation marks, and 2) short pauses, showing a less uniform distribution, usually occurred at left-branching phrase boundaries.