Reflective liquid-like films of silver nanoparticles simultaneously have metallic luster and the macroscopic properties of a fluid. Owing to their special properties, the films can be potential materials for the component of a new kind of liquid mirrors. The influence of different sizes of nanoparticles on the films reflectivity has been considered in this study. A great improvement on the reflectivity of the films has been found with the increase in the silver nanoparticles’ size. Additionally, the volume of the liquid substrate also has an effect on the reflectivity of the films. Characterization of the films by X-ray diffraction indicates that the liquid-like films are mainly composed of fcc silver nanoparticles rather than silver compounds.