The selectively excited luminescence in Cd_1-xMn_xTe(0.25 < x < 0.36) is interpreted in terms of the magnetic polaron formation. The energy parameter Δ₀ which characterizes the magnetic relaxation was measured as a function of manganese concentration, temperature, and magnetic field. We found that antiferromagnetic pairs of neighbouring Mn²⁺ contribute to the magnetic polaron.