Abstract: The dynamics of elongation of individual internodes of maize were studied under drought stress in field experiment in Marrakech (Morocco), for three irrigations treatments. T1 is a control treatment, which was irrigated once a week. T2 was irrigated until the appearance of collar of the 6th leaf. The irrigation was stopped for three weeks and then initiated again when the collar of the 10th leaf appears on plants. T3 was irrigated until the appearance of the collar of 10th leaf. The irrigation was stopped for three weeks and started when silks emerge. After these three weeks, the irrigation retook place once a week for all treatments. Internode extension in maize was described in four phases. Phase (I), during which elongation was exponential, phase (II), which was short during which the extension rate increases rapidly. A constant elongation rate defined phase (III), followed by phase (IV) in which elongation rate decreased. The co-ordination between collar emergence and the end of the exponential phase stay valid in each treatment. This confirms the contention that the kinetics of internode elongation is constantly controlled by the emergence of leaf collars. The final length of internodes was correlated to the linear elongation rate in each treatment (up to 90%).