An intermediate for immobilizing biofunctional molecules, 3-aminopropyltrimethoxysilane (APTMS) was anchored to ZnO nanorod arrays which had been grown by an aqueous solution method with microwave-assisted heating on a-plane sapphire substrates. X-ray photoelectron spectroscopy analysis revealed that the quantity of APTMS anchored on the ZnO nanorod arrays was more than that on a flat ZnO layer. Also, annealing of the APTMS anchored to ZnO nanorods at 500 degrees C showed that the amino groups were disappeared while Si atoms remained after the annealing probably due to strong Si-O bonding.