As a great heat reservoir, the ocean plays an important role in climate change and variation. While the atmospheric concentration of greenhouse gases increases, the ocean absorbs heat from the atmosphere and stores it into the abyssal zone, leading to a reduced atmospheric warming. This study aims to investigate the regional efficacy of ocean heat uptake and the relative contribution of the ocean basins simulated by the global climate models submitted to the Coupled Model Intercomparison Project-phase 5 for an idealized experiment with a quadrupling of atmospheric carbon dioxide. A preliminary result shows that the efficacy of ocean heat uptake differs with depth and ocean basin depending on the activity of deep convection within the basin. The model results normalized by each model’s total heat content change will be presented with more details and the inter-model differences will be discussed. leading to a reduced atmospheric warming. This study aims to investigate the regional efficacy of ocean heat uptake and the relative contribution of the ocean basins simulated by the global climate models submitted to the Coupled Model Intercomparison Project-phase 5 for an idealized experiment with a quadrupling of atmospheric carbon dioxide. A preliminary result shows that the efficacy of ocean heat uptake differs with depth and ocean basin depending on the activity of deep convection within the basin. The model results normalized by each model’s total heat content change will be presented with more details and the inter-model differences will be discussed.