A variable-focus liquid lens is provided. The liquid lens includes a membrane and a fluid. The membrane is made of a transparent elastomer, and the fluid fills a predetermined space to contact at least a lens surface of the membrane. The membrane and the fluid are respectively made of materials repulsive to each other, for example, hydrophilic and hydrophobic materials or oleophilic and oleophobic materials. Accordingly, a repulsive force between the fluid and the membrane can prevent the absorption or leaking of the fluid into/through the membrane.