This report contains tables which may be used to estimate the probability distribution of spectral amplitude for preliminary seismic risk studies. These tables should not be considered definitive, as are, for example, tables of trigonometric functions; rather they represent the results for one particular set of amplitude scaling functions and one particular geometry for seismic region. Spectral amplitudes have been calculated for seismicity in shallow diffuse source regions using the amplitude scaling functions of Trifunac and Lee (1979a). Separate tables are given for cases where the occurrence rate of earthquakes is described in terms of magnitude statistics and in terms of Modified Mercalli Intensity statistics.; The tables cover a range of seismicity models and maximum earthquake sizes (Magnitude or Modified Mercalli Intensity) that should be adequate for preliminary risk studies in regions where earthquakes are primarily shallow events and where amplitude attenuation is not too different from that in parts of the United States.