We have developed a new, advanced multi-purpose digital polygraph system, composed in 16 channels of bio-amplifier and a Windows 2000 or XP based personal computer to control the system. Added to the conventional polygraph examination indices of respiration movements, electrodermal responses and finger plethysmogram, the new system is capable of measuring, recording and analyzing electroencephalogram, electromyogram, electrooculogram, eye blinks, heart rate, skin potential activities, skin conductance level, normalized pulse volume and other psychophysiological responses. The circuit for skin conductance measurement conforms to the recommendations of SPR. Since this system is used for polygraph examination in criminal investigation, the system's data acquisition program is equipped with the functions to support the tester, as well as the functions to prevent tampering of the data, along with the general functions of a digital polygraph system.