In this paper, a novel time delay reflector based on frequency selective surface (FSS) for time-domain pulse splitting is proposed. By employing dipole arrays and half-wave length resonators of the reflector, continuous incident wave with one polarization can be delayed for required time delay without affecting the incident wave with orthogonal polarization. This characteristic of the reflector is very attractive for two-beam multiplexing method in image radar applications. Detailed design procedures together with two examples are demonstrated.