Au/CeO2 catalysts are highly active for low-temperature CO oxidation and water gas shift reaction, but they deactivate rapidly because of sintering of gold nanoparticles, linked to the collapse or restructuring of the gold-ceria interfacial perimeters. To date, a detailed atomic-level insight into the restructuring of the active gold-ceria interfaces is still lacking. Here, we report that gold particles of 2-4 nm size, strongly anchored onto rod-shaped CeO2, are not only highly active but also distinctively stable under realistic reaction conditions. Environmental transmission electron microscopy analyses identified that the gold nanoparticles, in response to alternating oxidizing and reducing atmospheres, changed their shapes but did not sinter at temperatures up to 573 K. This finding offers a new strategy to stabilize gold nanoparticles on ceria by engineering the gold-ceria interfacial structure, which could be extended to other oxide-supported metal nanocatalysts.