Abstract: Micro-nano ZnO crystals were successfully prepared with Zn(CH3COO)2·2H2O as the unique reactant via a simple one-step thermal decomposition process using filter paper as sacrificial template. The phase, microcosmic structure and optical properties of the products were characterized by XRD, SEM and UV-vis, respectively. The results showed that the resulting products had high purity and faithfully duplicated the microcosmic morphologies of the filter paper. The effects of calcination temperature and reactant concentrations on the structure and morphology of as-prepared ZnO were investigated, and the synthesis mechanism of nano ZnO was also discussed elementarily.