Laryngeal DDK involve with the rate, pattern, and regularity (periodicity) in opening and closing of vocal fold. This study was aimed at investigating the characteristics of laryngeal DDK between nonfluent and fluent speakers. One with an ataxic dysarthria (with cerebellar lesion) and the other with stuttering, and 13 normal speakers were evaluated. L-DDK were analyzed with MSP (motor speech profile, CSL 4400). Measures of DDK included: DDKavr, DDKcvp, DDKjit, DDKavp. An ataxic dysarthric speaker and a stutterer showed more reduced rate and aperiodic L-DDK (both adductory and abductory movement) than normal speakers. But the average L-DDK period (ms) in adductory movement in a speaker with stuttering showed more decreased than the other. Results from this study are preliminary. Nonetheless, results of L-DDK produced by nonfluent speakers suggested the possibility to have relation with slow rate of phonatory initiation and connected speech. In the future, perceptual studies are needed in conjuction with acoustic and speech production.