The Co-doped ZnO nanopowders were synthesized by SolGel method with analytical grade zinc nit rate hexahydrate Zn(NO3)2·6H2O,C3H8O2 and cobalt acetate Co(NO3)2 as raw materials and C2H7NO as stabilizers. The effects of the dopant concentration of the transition metal ions Co and the annealing temperature on the crystal structure, morphology and photoluminescence performance of ZnO were investigated. The results indicate that ZnO nanopowders have cubic zinc hexagonal wurtzite structure, and the size of these spherical particles is about (15~20)nm. The diffraction peak intensity and particle size will increase gradually as the increasing of annealing temperature which has completed (101) preferred growth. The photoluminescence (PL) spectra showed that there was a strong glow peak in the ultravioletvisible light which changed with different dopant concentration and annealing temperature. The molar ratio of Zn ions to doped Co ions is 100∶2, the peak intensity of luminescence in the highest at 500 ℃.