Abstract: Nano-CaCO3 (nanometer calcium carbonate) composite acrylic coatings were prepared, and their application performance was tested.The result indicated that when the dosage of the modified nano-CaCO3 was 1.5%(mass), the coatings were obviously improved in such properties as light resistance, water resistance, self-cleaning and storage stability.The effects of adding light calcium carbonate, unmodified nano-CaCO3, modified nano-CaCO3 into the acrylic coatings and its dosage on the rheological property were studied.The results showed that the rheological property of this system conformed to the Casson model.When the dosage of modified nano-CaCO3 was 1.5% (mass), the coatings showed lower viscosity sensitivity to temperature, decreased viscosity, strong shear thinning ability,low Casson yield stress, and increased thixotropy, and the performance improvement was basically consistent with the change in rheological property.In addition,changing the solid content or adding butyl alcohol had basically the same influence on the rheological property of modified nano-CaCO3 composite acrylic coatings and the traditional acrylic coatings.