Abstract: A high-resolution hydrodynamic numerical model based on the Regional Ocean Modelling System (ROMS) for the Chinese offshore regions was built, using FIO-COM reanalysis data as boundary forcing. The model simulated tidal results align closely with the EOT20 satellite observations, showing that the tides in this region are predominantly influenced by tidal waves from the Pacific Ocean, which split into northern and southern branches. Furthermore, the locations of tidal amphidromic points were simulated accurately. To evaluate its performance in simulating sea surface temperature (SST) and sea surface salinity (SSS), the statistical analysis methods including bias ( \mathrmb\mathrmi\mathrma\mathrms ), mean error ( \mathrmM\mathrmE ), mean absolute error ( \mathrmM\mathrmA\mathrmE ), root mean square error ( \mathrmR\mathrmM\mathrmS\mathrmE ), and correlation coefficients (R) were utilized. The results indicate that the seasonal variations of the modeled SST and SSS are closes to the OI SST and SMAP SSS observational data. The spatial correlation coefficients between SST and OI SST observation data for different seasons exceed 0.989, while that for the annual mean SST and SSS reach to 0.997 and 0.95, respectively. Additionally, the model also successfully simulates the seasonal variations of the currents in the Chinese offshore area, as well as the structural characteristics and lifecycle processes of the Yellow Sea cold water mass.