<p>The oceanic general circulations in the Ross Sea, where the southernmost ocean is located, play an important role in the climate system. Yet, the energy cycle of oceanic circulations in the Ross Sea is still unclear. By employing an eddy-permitting coupled regional ocean-sea ice-ice shelf model, this study investigates the oceanic energy cycle in the Ross Sea. Based on the Lorenz Energy Cycle framework, the spatiotemporal distributions of kinetic energy and available potential energy within the Ross Sea are quantitatively analyzed. The power pathways and magnitudes of energy conversion are also quantified. The simulated results show that the Mean Available Potential Energy (MAPE) is the largest energy reservoir of about 527.62 PJ (1 PJ = 10¹⁵ J), followed by the Eddy Available Potential Energy (EAPE), the Mean Kinetic Energy (MKE), and the Eddy Kinetic Energy (EKE) of about 19.20 PJ, 1.04 PJ, and 0.82 PJ, respectively. In the sub-ice-shelf cavity, the maximal MAPE is up to about 177.81 PJ, and the EAPE, MKE, and EKE are about 2.58 PJ, 39.87 TJ (1 TJ = 10¹² J), and 23.05 TJ, respectively. The inputs to the regional energy reservoirs are mainly from the sea surface momentum and buoyancy fluxes. The baroclinic pathway plays a dominant role in the conversion of energy to EKE, both in the open ocean and in the sub-ice-shelf cavity. The energy conversion from EAPE to EKE in the open ocean and the sub-ice-shelf cavity is about 2.86 GW (1 GW = 10⁹ J) and 162.18 MW(1 MW = 10⁶ J), respectively. In addition, the kinetic energy is directed from EKE to MKE in the Ross Sea, and such an energy flow in the barotropic pathway is opposite from that in the Southern Ocean.</p>