Abstract:By using ERA-40 wave reanalysis data from ECMWF (European Centre for Medium-Range Weather Forecasts), the research on the wind wave, swell, mixed wave energy resources over the Northwest Pacific ocean was carried out with wave energy density calculating method. The results show as follows: (1) There was an obvious seasonal variation in wave energy density over the Northwest Pacific ocean, that was the high density of mixed wave energy in winter but low one in summer; the density of swell wave energy was larger than that of wind wave energy in spring, summer and autumn except winter. (2) Large-value center of mixed wave energy density mainly distributed in Aleutian Islands and its adjacent waters, which amounteal to more than 50 kW/m. Relative large value areas of mixed wave energy density in China Sea located in the line of Ryukyu Islands-Luzon Strait-Pullo Secca de Mare (southeast of South Peninsula), appearing in NE-SW direction and the annual average value was above 4kW/m, even up to 12 kW/m in the northern South China Sea. (3) Wave energy densities in the Bohai Sea, Yellow Sea, East China Sea and South China Sea exhibited obvious bimodal monthly variation characteristics. (4) The wave energy density above 2 kW/m repentodly occurred. (5) The significant wave height (SWH) above 0.5 m in the most of Northwest Pacific ocean are high, near 90%. (6) The stability of swell wave energy density is much better than that of wind wave energy, and the wave energy density in the ocean was much better than that in nearshore. The wave energy density in January was the most stable all year around, and it was the worst in October.