The CFOSAT(Chinese-French Oceanography Satellite)equipped with the high-performance wave spectrometer SWIM has obtained continuous and extensive wave data.While CFOSAT wave data have undergone numerous validations and calibrations globally,most comparisons have been made with buoy data.There is a lack of contrast with existing mature datasets when applying satellite data to the study of wave field characteristics.By focusing on the China's adjacent seas,comparing the significant wave heights(SWH)between CFOSAT and ERA5 data and analyzing their differences.The results show that the CFOSAT data and ERA5 data exhibit similar performance and high correlation in wave field observations;The difference in SWH between them shows seasonal variation characteristics,with a greater degree of dispersion in the autumn and winter seasons and a more stable in the spring and summer seasons;With the increase of wave height,the bias between CFOSAT and ERA5 data significantly increases.