Abstract: Nano-sized TiO2 and ZnFe2O4-doped TiO2 were prepared from Ti(OC4H9)4 and ZnFe2O4 by sol-gel method,where Ti(OC4H9)4 and ZnFe2O4 were used as principle precursors,isopropanol was used solvent and hydrochloric acid was used to adjust the number of pH to about 3.The structure,size and the appearance of TiO2 and ZnFe2O4/TiO2 were examined by XRD and TEM.The results show that the product made by sol-gel method is nano-sized,the adulteration of ZnFe2O4 accelerates the transition of TiO2 and decreases the particle size of TiO2 from 25nm to 15nm.The activities of photocatalytic oxidation of ZnFe2O4 doped TiO2 was studied by the degradation of Rhodamine B.The factors such as calcining temperature and the dopingamount of ZnFe2O4 were investigated.The results indicate that 500℃ is the optimum calcining temperature and the optimum doping amount is 0.5%.When the adulterate amount 1.5%,rutile phase was found in the product.It was possible that a semiconductor was formed.The experiments of the degradation of rhodamine B show that the adulteration of ZnFe2O4 increases the photocatalytic activity of TiO2.