This study presents a method to use GPS-output velocity signal as wave measurement data. A high pass filter was applied to GPS velocity spectrum in order to separate wave motion and satellite motion in the frequency domain. The vertical displacement spectrum of sea surface particle was obtained from velocity spectrum by applying a transformation function. In this study, laboratory experiments were designed to simulate perfect harmonic ocean wave motion by a dynamic simulator, in order to verify the present idea. It was identified average 4% bias on the vertical displacements between simulated and GPS derived, identifying the reasonable result from present GPS wave measurement approach. Field test was also carried out in this study. The GPS receiver was installed on a buoy and the derived significant wave height and mean wave period were compared with the buoy measurements by accelerometer. Field experiment showed approximate trend from buoy measured and GPS derived but an improvability results in quantification was found.