The temperature effect on the Cu2O oxide morphology was investigated by oxidizing Cu(100) thin films at the temperature ranging from 150 to 1000 degreesC and constant oxygen partial pressure of 5 x 10(-4) Torr. The evolution of the oxide island size and shape was followed inside an in situ ultrahigh vacuum transmission electron microscope (UHV TEM). Of particular interest, we find that the oxide morphology can be triangular, hut, rod or pyramid shaped depending only on the oxidation temperature. (C) 2003 Elsevier Science B.V. All rights reserved.