Large-scale synthesis of ZnO hexagonal pyramids was achieved by a simple thermal decomposition route of precursor at 240 ℃ in the presence of PEG400.The precursor was obtained by room-temperature solid-state grinding reaction between Zn(CH3COO)2.2H2O and Na2CO3.Crystal structure and morphology of the products were analyzed and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM).The results of further experiments showed that PEG400 had an important role in the formation of ZnO hexagonal pyramids.Difference between the single and double hexagonal pyramid may come from the special thermal decomposition reaction.The Photoluminescence (PL) spectra of ZnO hexagonal pyramids exhibit strong near-band-edge emission at ~386 nm and weak green emission at ~550 nm.The Raman-active vibration at ~435 cm-1 suggests that the ZnO hexagonal pyramids have high crystallinity.