Abstract: Ultrafine zinc oxide was synthesized with zinc nitrate as main raw material by combined precipitation and hydrothermal process.The properties of the prepared zinc oxide UV-shielding membrane were studied by ultraviolet spectro- photometer.Results showed that the UV-shielding membrane added trace zinc oxide powder had very good visible light transparency and ultraviolet shielding properties.The optimum technological conditions of zinc oxide ultraviolet shielding membrane preparation process were: Zn（NO₃）₂ concentration was 0.5 mol/L， amount-of-substance ratio of solid NaOH， Zn（NO₃）₂ crystal，and SDS was 15∶7∶1，the hydrothermal temperature was 120 ℃，hydrothermal time was 0.5 h，precipitation reaction temperature was 70 ℃，and precipitation reaction time was 0.5 h.

Key words: ultrafine zinc oxide, ultraviolet screening properties, zinc nitrate