Abstract: The protective materials with nano silicon dioxide additives for dinosaur fossils were prepared by blending and insitu aggregation methods. Two protective materials were coated on steel discs, respectively. Then the discs were soaked and corroded in 3.5% sodium chloride solution. Next, the corrosion potential and current, alternating current impedance and weightless corrosion rate were measured. The dispersibility and thermal degradation of the protective materials were measured by SPM and DSC. The results showed that the corrosion current of the protective materials prepared by blending and in situ aggregation method was 3.481×10^-7A/cm ² and 2.332×10^-6 A/cm 2,respectively. The corrosion current of nitrocellulose varnish was 4.181×10^-6A/cm². The corrosion rate of the protective materials prepared by blending method was one tenth of that of nitrocellulose varnish. The weightless corrosion rates of the three kinds of protective materials were 1.18 g/(m2·h), 1.19 g/(m2·h) and 1.29 g/(m2·h), respectively. The corrosion resistance of the protective materials prepared by blending method was the best, which was surpported by the test results of alternating current impedance. When processing water soluble protective materials with 4% nano SiO2, the heat resistance and dispersibility of the materials prepared by blending method were better than those of the materials prepared by in situ aggregation method. The coating adhesion of both kinds of materials is the first grade.