Abstract:?The Ocean Model Intercomparison Project (OMIP) is an endorsed project in the CMIP6. OMIP is dedicated to the important CMIP6 science questions of investigating the origins and consequences of systematic model biases. What’s more, OMIP primarily contributes to the regional sea level change and near-term projection grand challenges put forward by WCRP (World Climate Research Program). OMIP provides an experimental protocol for global ocean/sea-ice simulations, tracer experiments and interactive biogeochemical experiments forced with common atmospheric data sets to investigate the systematic model biases. Simultaneously, OMIP provides a detailed protocol for ocean diagnostics to be saved as part of CMIP6, and then it helps evaluate, understand, and improve the ocean, sea-ice/tracer, and biogeochemical components of climate and Earth System Models contributing to CMIP6.