An Ag layer with thickness of 1.5 nm is deposited on Si(111) substrate by magnetron sputtering in order to protect the Si surface from oxidation. ZnO films with mosaic structure are grown on Ag-Si(111) templates by atmospheric-pressure metalorganic chemical vapor depositon (AP-MOCVD). The micro-crack with orientation character is found on ZnO films with optical microscope, and the crack density is 100 cm-1. X-ray diffraction results show that the highly c-axis oriented ZnO films is obtained. The fullwidth at half-maximum of the (002) ω-scans of double-crystal X-ray diffraction is 1.37°. Free exciton and binding exciton emission accompanied by their LO phonons could be observed from the photoluminescence spectrum at 10 K. All the results show that the metal Ag is an effective buffer layer for the growth of ZnO films on Si(111) substrate with MOCVD method.