Porous metallic copper was successfully prepared by a simple thermal decomposition strategy. A coordination compound of Cu(BTA)2 with the morphology of micro-rod crystal was synthesized as the precursor. The precursor to copper transformation was performed and annealed at 600°C with the shape preserved. The copper micro-rods are assembled from unique thin lamellar layers, each with the thickness of approximately 200 nm and nano-pores of approximately 20 to 100 nm. This morphology is highly related to the crystal structure of the precursor. The mechanism of the morphology formation is proposed, which would be able to offer a guideline toward porous metals with controllable macro/micro/nano-structures by the precursor crystal growth and design.