Abstract: A new method of designing reflective multilayer polarizers working in extreme ultraviolet (EUV) range at a single wavelength using different merit functions has been developed. A merit function of product of s-reflection throughput and logarithm of reflection polarization ratio was chosen. Characteristics of Mo/Si multilayers calculated using the merit function at 13.0 nm have been compared with those calculated using the traditional method. The polarizers of high polarization ratio and large s-reflectivity can be designed by choosing the number of layers and optimizing the thickness of each layer to maximize the merit function.