Porous copper oxide has been synthesized via copper oxalate precursor, which was prepared in mild condition without any template or additive. Powder X-ray diffraction, scanning electron microscopy, and nitrogen physisorption method are used to characterize various properties of the obtained samples. SEM analyses show that the precursor morphology was maintained after calcination, and the obtained hierarchically copper oxide was built up of nanocrystals. Nitrogen physisorption analyses show that copper oxide samples were very porous. The porous material could be found application in catalysis field. (C) 2007 Elsevier Ltd. All rights reserved.