The room-temperature ferromagnetism (RTFM) of Co-doped zinc oxide are reported in this paper. The Zn1-xCoxO (x=0.02, 0.06, 0.10) specimens were synthesized by solid state reaction of the mixture of ZnO and Co2O3 powders. The specimens were then annealed in the hydrogenation ambience. The RTFM was found in the hydrogenated samples, and the hysteresis loops of the hydrogenated Co-doped ZnO samples were measured at 300 K by using the superconducting quantum interference device magnetometer. The samples were further measured by X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy.