The global energy cycle between the land and the ocean has been studied with simulations of the 20th century performed with coupled ocean-atmosphere climate models. The energy cycle consists of the net energy fluxes at the top-of-the-atmosphere (TOA) and the surface, the atmospheric energy storage rates over the global land and ocean, and the atmospheric energy transport between the land and ocean. The energy cycle was investigated using a multi-model ensemble for its centennial mean, climatological annual variation and long-term trend. Some distinctive features of the cycle were revealed: (1) the ocean-to-land atmospheric energy transport plays a key role in partitioning the global net TOA flux between the ocean and land, (2) the annual variation of the global net TOA flux is primarily attributed by the ocean surface flux, and (3) it is ascertained that the planetary energy imbalance on the long-term period is induced by the ocean's heat uptake.