Nanostructured CuO films with flower-like architectures were fabricated by immersing copper foils in an aqueous solution of sodium hydroxide and sodium dodecylsulfate, and subsequent heat treatment at low temperature. The as-prepared CuO films exhibited not only higher reversible capacity but also better rate capability than those of network-like counterpart as negative-electrodes of lithium ion batteries. The effect of surface morphology on the electrochemical performance of the CuO electrodes was discussed. It was confirmed that the unique flower-like structures are mainly responsible for the difference in electrochemical performance between the two kinds of electrodes. The result of this study provides an attractive electrode with high energy-density for lithium ion batteries via a simple and green procedure.