This study investigated two aspects of Mandarin Chinese: (1) the acoustic correlates of intonations of a sentence for three expressions, declarative, interrogative and exclamatory, and (2) the influence of intonation on the four tones in the sentence-final position. A corpus was prepared and 6 speakers recorded the corpus. Acoustical analysis was made for the 1,824 test items. Results show that the duration of syllable nuclei in a sentence varies according to word position rather than intonation except that in the sentence-final position. Both intonation and word position have influenced the fundamental frequency, tone range, and peak amplitude of syllable nuclei. The duration, fundamental frequency and peak amplitude of the four tones in sentence-final position are modified by intonation. However, the basic characteristic of the shape of the four tones remains very close to that of tones in isolated words.