4260 recordings of 165 events by 168 stations were used to calculate the spectral decay kappa parameter. The kappa values of the two horizontal components were similar and generally larger than those of the vertical component. The impact of magnitude and site condition on the <em>κ</em><sub>0</sub> value was also investigated, which showed that <em>κ</em><sub>0</sub> increased with magnitude, indicating that <em>κ</em><sub>0</sub> is influenced by source effects. In addition, the results showed that softer sites have higher <em>κ</em><sub>0</sub> values, indicating that site conditions significantly affect <em>κ</em><sub>0</sub> estimates. The single-station <em>κ</em><sub>0</sub> values showed little difference between the two horizontal components, both of which were significantly greater than the <em>κ</em><sub>0 </sub>value of the UD component. Furthermore, the relationships between <em>κ</em><sub>0</sub> and Vs30 were derived, which indicates that <em>κ</em><sub>0</sub> value decreases with increasing parameter Vs30. Moreover, the log<em>κ</em><sub>0</sub>-log<em>f</em><sub>0</sub> correlations estimate the <em>κ</em><sub>0</sub> better than the ln<em>V</em>s30-<em>κ</em><sub>0</sub> correlation does. Finally, we performed ground motion simulations at 16 stations to validate the derived site-based kappa model. Ground motion simulations at 16 stations demonstrate that both site- and event-related κ₀ mainly affect high-frequency amplitudes. These findings provide a basis for seismic attenuation study and refined ground motion simulation in the study region.