This study was carried out to develop a versatile data acquisition/processing system for overall tractor performance utilizing a NEC PC-8001 microcomputer. The data acquisition system measures drawbar pull and power, wheel torque and axle power, ground speed, wheel slip, fuel flow, and engine speed. The system stores hexadecimal data for these variables in memory. Upon completion of each test run, all hexadecimal data stored in memory are recorded on floppy disc. The data processing system reads in the data collected on floppy disc and interprete them using several graphical and statistical techniques. The system uses the same microcomputer and a dot-matrix printer. The data acquisition system has been installed on a GOLDSTAR 500 tractor (2WD, 50 ps). A field study has shown that tractor performance data can be quickly and easily collected. It also appeared that the data processing system can be used to efficiently analyze the collected data. The data acquisition system has some troublesome in mounting and handling on tractor since it uses a general-purpose computer consisting of several components.