In the inspection of the time intervals between two adjacent estimated Auditory Perceptual Timing Points (APTP), the time intervals were found to be dependent on the succeeding CV-syllable in continuously uttered sentences. In order to precisely investigate this dependency, the time intervals corresponding to the specified succeeding CV-syllables were measured by means of listening tests and the t-test was carried out. Furthermore, the effects of exceptional sounds were taken into consideration. Then a new rule for controlling the rhythm of synthetic speech by positioning each CV-syllable at an adequate time position was developed. The speech synthesized according to the positioning rule were evaluated and the result showed that 70% to 80% of listeners recognized its superiority.