Superfine copper powders can be used as the electronically conductive adhesives, ceramic materials and catalyst, and have shown a good application prospect instead of silver with copper in industry. The anti-oxidation nano-scale copper powders were prepared by using a protection-reduction technique from a copper ammonia complex solution, in which ascorbic acid (VC) was used as reducing agent, and polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA) or polyacrylamide (PAA) were protection agents, and oleic acid was passivation agent. The obtained copper powders are homogeneous and stable in air. The reaction temperature and the value of n (protection agent): n (Cu) have a great influence on the particle size and shape. When the ratios of n (PVP),n (PVA) and n (PAA) to n (Cu) range from 0.03 to 0.1, 0.02 to 0.09 and 0.02 to 0.08 respectively, the obtained particles will be cuboids or non-spheroid. The reason can be attributed to the partial protection of polymer.