Currently, the hydroformylation of short olefins is operated almost exclusively by using Rh catalysts. Considering the high cost and scarcity of rhodium resources, it is important to develop non-noble metal catalysts toward hydroformylation. Herein, we report an efficient cobalt-based catalyst rich in interfacial sites between metallic and oxidized cobalt species for the hydroformylation of short olefin, propene, under a moderate syngas pressure. The catalyst exhibited a high specific activity of 252 mol mol Co -1 h -1 in toluene under 2 bar of propene and 40 bar of CO/H 2 mixed gas (CO/H 2 = 1:1) at 160 °C. According to mechanistic studies, the interface of metallic and oxidized cobalt species promoted the adsorption of CO and propene. Moreover, the interfacial sites lowered the energy barrier for CO* hydrogenation and C-C coupling compared with metallic cobalt.