The proper design of man-machine systems requires as much understanding of the human element as of the machine. Although the modern systems engineer can obtain a very high degree of repeatability and accuracy for the characteristics of a machine, these of the human elements are much less well known. Due to the complexity and importance of modern man-machine systems, this difficult problem has recently received increasing attention. In this paper, the dynamic characteristics of the human operator have been newly determined by impulse estimation using Pseuo-random binnary signals as a test signal and the quasi-linear human operator models used as an element of a closed-loop control system adopted from McRuer & Krendel and Bekey. Also the techniques and instruments are presented for correlating the actual characteristics of the constructed system with anticipated theoretical values. Consequently, in spite of many problems remain yet, experimental results were very satisfactory.