TOPEX/POSEIDON altimeter data from October 1992 to June 2002 are used to calculate the energy flux of M2 internal tides along the margin of Northwestern Pacific. This arc borderline of the Pacific Basin is characterized by sharp changes in bottom topography, which constitute good boundary conditions for internal tidal energy concentration. We extract baroclinic tides, that yield energy transmission, from temporarily coherent internal tide signals in the altimeter data. We use the field measurements of current velocities in the South China Sea (SCS) to test the method. The results show that satellite-derived M2 tide components agree with the field data very well. Computation results indicate that the maximum energy flux of M2 internal tides, 3 kW m-1, appears in the Ryukyu Trench. The total energy flux of M2 internal tides along the margin of Northwestern Pacific is about 15GW.