F0 values of filled pauses (FP) in the Corpus of Spontaneous Japanese were analyzed to examine the mechanism by which the F0 heights of FP were determined. Statistical analyses of the F0 values of FP occurring in between two full-fledged accentual phrases (AP) revealed correspondence between the occurrence timing of FP and the F0 height. Based upon this finding, 5 models of F0 prediction were proposed. Comparison of the mean prediction errors revealed that the best prediction was obtained in a model that linearly interpolate the phrase-final L% tone of the immediately preceding AP and the phrase-initial %L tone of the immediately following AP. This finding suggests that the F0 of FP was specified at the level of phonetic realization rather than phonological prosodic representation.