According to the test requirements of measuring the moment of inertia and based on graphical programming language LabVIEW8.2, a measurement system of moment of inertia is designed. The system transfers the collected data to PC through the LabVIEW serial communication programming. The data are transformed, curve fitted and calculated by the LabVIEW measurement system, which realizes the acquisition, exhibition and storage of data in real-time. With the method of LabVIEW, combined with MATLAB to fit curve, the processing program of curve fitting is simplified. The system meets the test requirements of measuring the moment of inertia.