This paper describes a recently developed automated triaxial testing system. Loading is controlled by a closed-loop feedback scheme capable of performing stress- or strain-controlled tests in the standard triaxial environment. The system has two control channels allowing separate control of both the axial load and the chamber pressure. Software written especially for this system can control back pressure saturation, consolidation, shear loading, cyclic loading, and a number of special loading programs. Each software package is well documented with complete notes for interactive dialogue with the computer. The data retrieving and plotting software is capable of processing data and converting it to 20 variables commonly used in geotechnical engineering. These variables can be plotted with different combinations for display and detailed study. Typical test results for a fine sand are included to demonstrate the abilities of the system. The system is well suited for research purposes, however it can also be used effectively in geotechnical material testing in consulting laboratories. The computer-based testing system is simple in operation, rapid in sampling, accurate in performance, and reasonable in cost.