A facile hydrothermal decomposition route was developed to synthesis ZnO whiskers at moderate conditions.ZnO whiskers with a length of 40-50μm and a diameter of about 1μm were produced by co-precipitation of ZnSO4 and Na2CO3 solutions at room temperature followed by hydrothermal treatment of the as-prepared Zn5(CO3)2(OH)6 precursor at 160℃ for 12 h in the presence of minor amount of EDTA.ZnO whiskers were synthesized via the hydrothermal decomposition: Zn5(CO3)2(OH)6 + 4OH-=5ZnO +5H2O + 2CO32-.