Using the tools of the J-matrix method, we obtain analytic expression for the relativistic scattering phase shift of M-term separable potential with Laguerre-type form factors for M = 1, 2, and 3. The Dirac Hamiltonian with spherical symmetry is taken as the reference Hamiltonian. For higher order separable potentials (M > 4) an exact numerical evaluation could be obtained in a simple and straightforward way.