The nanometer yellow iron oxide was prepared by oxidizing Fe(OH)2 with air,which was verified with XRD and TEM.The result shows that nanometer yellow iron oxide is spindle-shaped and well-distributed with a long axis of 150-200 nm and short axis of40-50 nm.Ultraviolet (UV) transmittance of the iron oxide shows the great effect of concentration on both transparency and UV absorption,and it has been proven that iron oxide with a concentration of 0.025wt% is preferred.The spectrum of XRD indicates that it is goethite.When the yellow iron is dispersed in sol,given that the wavelength of UV is less than 300 nm,its UV absorption capacity is superior to those of ZnO and TiO2.The absorption capacity of the yellow iron is less than TiO2 and more than ZnO as the wavelength of UV is 300-400 nm.