Directional wave spectra measured by a cloverleaf buoy in the East China Sea during AMTEX '75 have been compared with those calculated with the operational numerical MRI wave model developed at the Meteorological Research Institute of the Japan Meteorological Agency (J.M.A.).It is shown that the numerical wave model MRI can predict rather well, not only the frequency spectrum, but also the angular distribution function of the spectrum.The frequency dependence of the calculated angular distribution function is quite similar to that observed; the angular distribution is narrower for the spectral components near the peak spectral frequency but widens toward high frequencies and approaches the cos2e-distribution.