A GPS buoy is moored at a spot of 100-400m in water depth and within 10-20km from coastal line and measures the vertical motion of the buoy owing to waves and tides by the RTK-GPS technology. Twelve GPS bouys are operated on the Tohoku to Shikoku District coast of the Pacific Ocean as the newest equipments on the Nationwide Ocean Wave Information Network for Ports and Harbours (NOWPHAS). This study made a comparison between the deepwater and reratively shallow water wave characteristics, which were obtained by the GPS buoys and coastal wave gauges respectively, from the year 2008 to 2010. The major results are as follows:
　(1) The difference among the GPS buoys on Tohoku District coast in the monthly-mean significant wave is small. A high and long monthly-mean siginificant wave was observed at these buoys in winter.
　(2) The correlation of the significant wave height at a GPS buoy and its nearby coastal wave gauge is determined by the deepwater wave direction. The correlaton does not significantly change by considering the wave propagation time between these two locations.
　(3) The deepwater wave characteristics at the GPS bouy off Fukushima are similar to those at the step-type wave gauge at Iwaki-oki.
　(4) The monthly-mean wave energy flux is larger and the wave calmness rate is lower, at GPS buoy sites than at their nearby coastal wave gauge sites.
　(5) There is a correlation between the maximal siginificant wave height during high wave events at the GPS buoys and their nearby coastal wave gauges except for some cases.