Large-quantity growth of ZnO nanorods is achieved by oxidation of Zn powders with catalyst-free method.The products are characterized using X-ray diffraction,scanning electron microscopy,transmission electron microscopy and photoluminescence spectroscopy.The as-grown nanorods are structurally uniform with diameter ranging from 60 to 150nm and lengths of up to 5-8μm,and they are single crystalline in nature with growth direction parallel to [0001].Room-temperature photoluminescence spectrum of the nanorods shows a strong and sharp UV emission band at 385 nm and a weak and broad green emission band at 495 nm.The vapor-solid model is also proposed to explain the growth behavior of ZnO nanorods in our synthesis process.