In this paper, the wave observation system by arrayed buoys whose three dimensional movements are measured precisely by the kinematic GPS is proposed. Firstly, the general concept and system configuration of this observation system are described. The proposed wave observation system measures the three-dimensional movements of each observational buoy relative to the fixed reference station by the kinematic GPS. Because the distance between the reference station and each buoy is about several kilometers at most, the measurement error of the kinematic GPS can be estimated less than a few centimeters. The data of each observational buoy are sent to the reference station by radio telemetry system, and then the data are used to estimate effective information about wave such as period, wavelength, height and direction. Finally, it is shown that this proposed system is able to estimate the propagation directions of waves of the same period propagated from various directions by high resolution and analyzing ability.