In this study, speech rate, articulation rate, disfluency occurrences, fluency evaluations and fluency patterns are investigated to unveil the relationships between fluency, temporal features and prosodic features in simultaneous interpretation（ SI）. Seven types of disfluencies which are generally known to be potential factors affecting SI fluency are carefully examined. Results show that the most frequent pattern of SI disfluency is interpretation segments begun by fluent speech segments, followed by interpretation segments begun by negative fillers. Factor analysis and regression analysis found that two factors which are statistically influential to SI fluency are the Disfluency Factor（negative fillers, corrections and cuts） and the Speaking Rate Factor （the interpreter’s speech rate and articulation rate）. This study is the first effort that has ever examined the relationships between speech rate, fluency and prosody in English-Japanese simultaneous interpretation. The findings will be beneficial to future studies.
