Polarized light could be described completely by Stokes Parameters. A Division-of-Amplitude Polarimeter (DOAP) system was designed,in which one quarter-wave plate was set between the lenses of Division-of-Amplitude,and then the light path was in same plane. Intensity of four light beams related to Stokes Parameters was tested by four detectors with the same performance. The system was calibrated by known polarization that combined polaroid with one quarter-wave plate. Through matrix calculation,the Stokes parameters were tested quickly and the polarization of light was work out. Experiment shows that the system is set up easily and adjusted conveniently. The deviations of four dimensions of Stokes parameters between testing value and theoretical value are less than 6%.