By injecting additional argon gas, we were able to grow one-dimensional ZnO nanorod arrays with a uniform distribution on a large scale at a low temperature of less than 330 degrees C by metalorganic chemical vapor deposition. All of the nanorods grown or the sapphire substrate had a 30 degrees in-plane rotation with respect to the substrate and showed the epitaxial characteristics of [1010](ZnO)//[1120]sapphire, despite the low-temperature growth. These ZnO nanorods with high crystalline quality exhibited a high enhancement factor and low turn-on field value, thus having good potential to be used as a field emitter.