In this study the temporal effect of speaking rate, focus and prosody is analyzed. The test syllables are /pi, pa, pu/, which are embedded in disyllabic words, and the subjects are eight native speakers of standard Chinese. Consonantal VOT and vowel duration, together with duration of the preceding and following segments, are analyzed. Results show that the effect of speaking rate and focus is significant in all of the cases. The effect of prosodic position on VOT disappears when there is also the effect of speaking rate and\or focus. Within a prosodic domain, the prosodic effect on the final segments is greater than that on the initial ones.