正 Interest in nanowires of semiconducting oxides is exponentially grown in the last years, due to their attracting potential applications in electronic, optical and sensor field. We have focused our attention on the sensing properties of indium and zinc oxide nanostructures. We have studied the influence of the deposition conditions on the nanostructures morphology and sensing properties. We report on the growth of ZnO and In_2O_3 nanostructures on silicon and alumina substrates, using vapour phase technique. We have synthesized, depending on the growth conditions, different structures such as nano-wires, tetrapod, nano-comb, nano-necklace, nano-pencil ZnO/In_2O_3 without using any metal catalyst.