Zinc oxide films with c-axis preferred orientation were deposited on silicon (100) substrates by radio frequency (RF) reactive sputtering. The properties of the samples were characterized by X-ray diffractometer, X-ray photoelectron spectroscopy and fluorescent-spectrophotometer. The effect of sputtering power and substrate temperature on the structural and photoluminescent (PL) properties of the ZnO films was investigated. The results indicated that when the sputtering power is 100 W and the substrate temperature is 300-400℃, it is suitable for the growth of high c-axis orientation and small strain ZnO films. A violet peak at about 380 nm and a blue band at about 430 nm were observed in the room temperature photoluminescence spectra, and the origin of blue emission was investigated.ZnO films, XRD spectra, PL spectra, substrate temperature, RF reactive sputtering ZnO has been widely used in the surface-acoustic apparatus, gas sensor, solar cell electrode and light emitters for its excellent optical and electronic properties [1] . As a kind of direct band semiconductor compound with hexagonal wurtzite structure, ZnO has a wide band gap E g (3.37 ev) and high excition binding energy ex b E (60 meV) at room temperature, compared with other wide band emission materials [2,3] such as ZnSe (E g = 2.7 eV, ex b E = 20 meV) and GaN (E g = 3.4 eV, ex b E = 21 meV), and it would be more suitable for the room temperature or high temperature ultra-violet emission material, so its emission properties have drawn much attention.The emission peaks of ZnO films mainly contain an excition peak (∼380 nm) [2][3][4][5][6][7] and a green peak (∼510 nm) [6,7] . With the further study of the ZnO films photoluminescent (PL) properties, blue peaks at various wavelengths have been reported, e.g. Wang et al. [8] reported the blue peak at 446