Abstract: The biomimetic CeO2 was obtained by using fish scales as biotemplate, and its structure and properties were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and nitrogen adsorption-desorption measuring. The results show that the CeO2 was the cubic fluorite structure with grain sizes of 5—7 nm, and a lot of pores with 2-5 nm were found in it. The prepared CeO2 displayed the superior photocatalytic activity for the degradation of acid fuchsin under sun-light irradiation, with a degradation rate as high as 90% within 150 min.