This paper examines lip and jaw kinematics in the production of labial stop consonants where the duration of the oral closure is varied for linguistic purposes. The subjects were speakers of Japanese and Swedish, two languages that have a contrast between short and long consonants. Lip and jaw movements were recorded using a magnetometer system. Based on earlier work showing that the lips are moving at a high velocity at the oral closure, it was hypothesized that speakers could control closure duration by varying the position of a virtual target for the lower lip. According to this hypothesis, the peak vertical position of the lower lip during the oral closure should be higher for the long than for the short stops. This would result in the lips staying in contact for a longer period. Results from five subjects suggest that this is the case for those who produce nonoverlapping distributions of closure duration for the two categories. However, the peak velocity of the lower lip raising movement did not always differ between the two categories, suggesting that differences in muscle activation duration rather than virtual target position is another potential control variable. [Work supported by the NIH.]