Using frequency-time analysis method and vertical component Rayleigh wave records at 102 seismograph stations from nearly ten thousands earthquakes in the Eurasia and western Pacific marginal sea region, the authors measured fundamental mode Rayleigh wave group velocity dispersion curves in a period range from 8 s to 200 s for 11 213 paths. Through the inversion, it is obtained 28 maps on spatial variation of group velocity and its azimuthal anisotropy for the periods from 8 s to 200 s in the