Objective: Diadochokinetic syllable rates are used to evaluate a client’s ability to make rapidly alternating speech movements. There are two primary ways to obtain these measures. The first is by counting the number of syllable repetitions a client produces within a predetermined number of seconds and the second method is timing how many seconds it takes the client to repeat a predetermined number of syllables and the objective of this study is to obtain the diadochokinetic syllable rates standard among the intermediate students in 3,8,19 educational regions in Tehran.

Materials & Methods: The population of this study is composed of three educational regions 3,8,and 19.Among of them 1997 students (980 girls and 1017 boys ) selected randomized and examined.In the first method we must examined how many repetition of /pa/,/ta/,/ka/ and /pataka/ can the students produce in 5 seconds? And in the second method we must examined how many seconds does it take to produce 15 repititions of /pa/, /ta/, /ka/ and /pataka/?

Results: The findings of this research indicate that with increasing the grade (age) mean of syllable repetition number was increased and the mean of syllable repetition time was decreased.There was significant difference between means of boys and girls syllable repetition.

Conclusion: With increasing the grade (age) mean of syllable repetition number was increased and the mean of syllable repetition time was decreased.