Diadochokinetic rate has traditionally been used for assessment, diagnosis and therapy in patients who suffered from oral cancer resection, glossectomy, oral myofunctional disease, dysphagia, dysarthria, functional articulation disorders or apraxia of speech. This is because diadochokinetic rate shows the documented structural and physiological changes in the central nervous system and the peripheral components of oral and speech production mechanism. Diadochokinetic rates were obtained from seventy-six normal subjects by counting the repetition of oral function (/a:-u:/; /u:-i:/; and /i:-a:/), tongue function (tongue movement from side to side of lip corner and lan lan lan lan la), and lip-tongue function (/p-t-k/ and /ph-th-kh/) in 15 seconds. The Count-by-Time test was used for data collection. The finding showed average diadochokinetic rates (syllables or times per 15 seconds) were 33.6, 33.16, 30.58; 24.21, 15.10, 26.50 and 26.30 for /a:-u:/, /u:-i:/, /i:-a:/, tongue movement from side to side of lip corner, lan lan lan lan la, /p-t-k/, and /ph-th-kh/. Most of the correlation analysis showed a high positive relationship. The results of this study are guidelines of normal diadochokinetic rates. In addition, they can indicate the severity of diseases and evaluation of treatment.