Antiglare rearview mirrors incorporating liquid crystal(LC) cells which vary the reflectance of the mirrors according to the applied voltage have been developed. Seven different modes of LC mirrors were studied for this purpose. For each mode, the equations of the maximum reflectance and the minimum are derived theoretically and calculated numerically. Based on these results, we obtain a possible variable range of the reflectance which is one of the important requirements. The best modes are selected among the seven modes after evaluations and comparisons on fundamental matters, such as composition for the LC mirror and quality of the image added to the variable range of the reflectance. Brief description on the developed LC mirrors is given finally.