Room temperature oxidation behaviour of copper (Cu) nanorods was studied using transmission electron microscopy. It was shown that unlike that of bulk Cu, the oxide layer of Cu nanorods is porous and unstable resulting the total loss of resistance to oxidation. The oxidation was so devastating that Cu nanorods were quickly consumed by oxygen and collapsed after they were exposed in dry air for only a short period of time. It was also shown that by alloying with a little quantity of gallium (Ga), the antioxidation resistance of Cu nanorods could be greatly improved. (C) 2003 Elsevier B.V. All rights reserved.