Investigating the characteristics of significant wave height（SWH）is of great significance for early warning of marine disasters and the safety of marine production. The world-leading SWIM wave spectrometer onboard China-France Oceanography Satellite（CFOSAT）has the ability to provide wave properties on a global scale. However，there is a relative paucity on the coastal and regional assessments of the SWIM data. In this study，wave data from 39 buoys around Chinese offshore waters are employed to evaluate the quality of SWIM Level 2 products over 2020. Spatial and temporal matching criteria of 100 km and 5 min are applied. The results showed that after applying varying degrees of control to the land contaminations，there is a remarkable improvement in the accuracy of SWIM data. After completely filtering out the land contaminations，the nadir box SWH exhibits excellent consistency with buoy observations，where RMSE is 0.346 m，R is 0.943，and SI is 0.182. The overall difference between SWIM data and buoy observations increases with the SWH. Concerning the off-nadir observations，the spectrum SWH from 6°，8°，10° and combined SWH beams correlate well with the buoy observations，but the accuracy is slightly lower than the nadir box SWH. All these findings provide solid evidences that SWIM Level 2 products have strong credibility in Chinese offshore waters.
