Abstract: ZnO nanosheet films were synthesized on quartz glass substrates with ZnO seed-layers with a hydrothermal method. Their morphologies，structures，and optical properties were investigated with scanning electron microscope，X-ray diffractometer，transmission electron microscope and photoluminescence spectrometer，the possible growth mechanism was explored. The results show that these ZnO nanosheets are single crystalline with hexagonal wurtzite structure， they prefer?entially grow along the < 101 ˉ0 > directions. The room-temperature photoluminescence spectrum are composed of a sharp ultraviolet emission peak（380 nm）and a wide visible emission band. The visible emission band can be divided into three emission peaks centered around 550，620 and 760 nm，respectively.

Key words: ZnO, nanosheet, hydrothermal method, photoluminescence