A homogeneous porous Co3O4-ZnO nanomaterial (Zn-CoOx) was successfully fabricated by precipitation-annealing route. The as-prepared Zn-CoOx exhibited good response, reliable reversibility and good selectivity towards alcohols, which attributed to the porous structure and p-n heterojunction formed between Co3O4 and ZnO. In particular, the different Fermi levels of Co3O4 and ZnO leaded to a further increase the depth of the space charge layer, which improved the gas sensitivity of the material from 10％to 480％. Besides, the continuous Co3O4 leaded to a relatively lower operating temperature and resistance. This material preparation method and bimetallic oxides could be widely used in the research and development of metal oxide gas sensitive materials and sensors.