The objective of the present study was to analyze interspike intervals (ISI) of the human motor unit (MU) discharges in respect with the motor task. The subjects (n=4, 1 m, 3 f, 8 MUs, 2452 ISI) after preliminary practicing were instructed to voluntarily recruit the ordered number of MU discharges of m. triceps brach. (from 1 to 7, 40 attempts for each task), with the help of audio- visual feedback from the EMG device. From 50 to 90% attempts were correct. In these correct attempts in the task "2 discharges" the ISI was 99.45 ms. In the task "3 discharges" the 1st ISI was 100.57 ms, and the 2nd was longer (127.57 ms, p<0.01). In the tasks "4, 5, 6 and 7 discharges" the ISIs presented a wave-like sequence: the first three ISIs were increasing in a row, but the 4th was always shorter than the 3rd ISI. The 5th and the 6th ISI were again longer than the 4th ISI. Also, the 1st ISI was decreasing with the increasing number of discharges in the task (from cal. 100 to 80–85 ms). In conclusion, the ISI sequence may reflect the code of "motor command". Further it would be essential to compare the ISI sequence in the correct attempts to the "mistake attempts" (with 1–2 extra and 1–2 lacking MU discharges) and also to the "no-task attempts".