Abstract: Disclosed herein is an antireflective photocatalyst composition including a titanium dioxide-based photocatalyst, a binder, water, and alcohol, and a substrate using the composition. The antireflective photocatalyst composition is advantageous in that, when it is applied to a glass substrate, such as a glass antireflective film for a solar cell or a glass illuminator, it can prevent incident light energy from scattering and improve optical transmissivity, and in that it decomposes pollutants due to the dual action of harmful gas decomposition and self-purification, which are specific characteristics of a photocatalyst.