The relativistic motional plasma model is proposed ane defined. Using the charge fluid perturbation theory, the two-dimensional (2D) self-disturbance of the system and the phenomenon of beam-wave interaction are suudied. From this, the dielectric tensor of 2D relativistic motional plasma is given. We found that the relativistic motional plasma is an electromagnetic dielectric with a complex dispersion relation, and it displays a non-uniform complex electromagnetic space. In this paper, the response of relativistic motional plasma to the wave frequency is obtained by the numerical computation.