People tend to control their speech rate to help those with listening problems such as hearing impaired people. The aim of this study was to investigate effects of speech rate on the sentence perception by 10 adults with cochlear implantation. The sample speech included 42 sentences at normal, slow, and very slow speed focusing on the overall duration, vowel or pause duration. The subjects listened to the speech and wrote down what they heard. Each correct syllable of the content words in the sentence was counted to obtain the score. Partial points were given to the incomplete syllables. Results of this study were as follows: 1. The changes of speech rate had some influence on the sentence perception score by the cochlear implanted people. 2. In slow pause condition, the controlled speech rate had a positive effect on the perception score.