Abstract: Currently, one of the major trends in the development of climate system models is the improvement of the simulation capability for multiscale interaction processes and extreme events in the climate system. This enhancement is mainly achieved by increasing the spatial resolution of these models. Over the past five years, scientists from the Institute of Atmospheric Physics (IAP) at the Chinese Academy of Sciences have developed and improved the 25-km resolution atmospheric circulation model “Finite Volume Atmosphere Model of IAP LASG version 2.2” (FAMIL2.2). Furthermore, they have improved the 1/10 \text° resolution ocean circulation model “LASG/IAP Climate system Ocean Model version 3.0” (LICOM3.0). These advancements have culminated in the establishment of the high-resolution climate system model “Flexible Global Ocean-Atmosphere-Land System Model version f3-H” (FGOALS-f3-H). These high-resolution models have been used in many numerical experiments for climate simulations and forecasts/predictions. Their applications include the high-resolution model comparison project (HighResMIP) of the sixth phase of the international Coupled Model Inter-comparison Project (CMIP6) and the establishment of an ocean circulation prediction system known as the LICOM Forecast System. Preliminary diagnoses and analyses show that compared to their low-resolution counterparts, high-resolution models can better simulate mean climatology and climate variability. In particular, the high-resolution atmospheric model can better simulate typhoons and extreme precipitation events. Furthermore, the high-resolution oceanic model can better simulate the western boundary currents and mesoscale eddies. Finally, the high-resolution coupled model can more accurately reproduce mesoscale sea–air interaction processes and tropical instability waves.