Abstract: ZnO nanorods with hexagonal wurtzite structure were synthesized by the facile chemical bath deposition method. In order to alter their gas response towards the various test gases, the surfaces of ZnO nanorods were decorated with different nanoparticles, such as Ag, CuO and NiO. The gas response and selectivity of the surface modification of ZnO nanorods were investigated. The results showed that their gas sensing performances were improved obviously after the surface decoration. Especially, the ZnO nanorods decorated by CuO nanoparticles have the higher selectivity and sensitivity to hydrogen sulfide gas than the other test gases.