In　this　study,　334　accelerograms　of　42　small-to-moderate　earthquakes　recorded　at　36　strong-motion　stations　were　used　to　investigate　the　ground-motion　characteristics　of　the　southwestern　margin　of　the　Sichuan-Yunnan　rhombic　block　(SWM-SYRB),　one　of　the　most　active　seismic　regions　in　China.　The　high-frequency　attenuation　parameter　was　estimated　using　the　spectral　decay　method,　and　the　site　component　(kappa　0)　was　fitted.　The　kappa　0　estimates　decrease　with　the　increasing　time-averaged　S-wave　velocity　of　the　uppermost　30　m　(VS30).　Using　the　generalized　inversion　technique,　the　source　spectra,　quality　factor　(Q),　and　site　amplification　were　derived　from　the　Fourier　amplitude　spectra　(FAS).　The　obtained　average　stress　drop　for　earthquakes　occurred　in　SWM-SYRB　was　the　second　largest　among　various　boundary　areas　of　SYRB.　The　inverted　Q　model　was　Q(f)　=　115.1f0.616.　The　low　Q　structure　that　extends　southwestward　from　the　Songpan-Garze　block　to　SWM-SYRB　could　be　respon-sible　for　the　strong　regional　attenuation　of　ground　motion　with　distance.　At　frequencies　above　10　Hz,　the　average　site　amplifications　were　influenced　by　the　high-frequency　attenu-ation　effect.　The　site　amplification　of　site　class　D　reached　a　factor　of　6　at　0.7　Hz.　Moreover,　it　was　observed　that　site　amplification　factors　can　be　even　higher　when　peak　ground　accel-eration　is　larger　than　0.8　m=s2.　Finally,　the　obtained　parameters　were　used　in　the　stochastic　finite-fault　simulation　method　to　reproduce　the　FAS,　5%-damped　pseudospectral　accelera-tion,　and　time　series　of　the　2021　Mw　6.1　Yangbi　earthquake.　The　simulated　spectra　properly　matched　the　observations　in　a　broad　frequency　band　of　0.1-25　Hz.　Furthermore,　the　simu-lated　time　series　could　generally　represent　the　amplitude　of　the　S-wave　portion　of　observed　ones.