The radiation magnetohydrodynamics (RMHD) system plays an important role in the high temperature flow systems, inertial confinement fusion and astrophysics. The main challenge is that the radiation travels at the speed of light while the magnetohydrodynamics changes with the time scale of the fluid. The time scales of these two processes can vary dramatically. In order to use mesh sizes and time steps that are independent of the speed of light, asymptotic preserving (AP) schemes in both space and time are desired. We develop AP schemes for the RMHD system and the frequency-dependent radiative transfer system. The performance of the semi-implicit method is presented, for both optically thin and thick regions.