  In this paper, we prove the energy conservation for the weak solutions to the
three-dimensional equations of compressible magnetohydrodynamic flows (MHD)
under certain conditions only about density and velocity. This work is inspired
by the seminal work by Yu [27] on the energy conservation of compressible
Navier-Stokes equations. Our result indicates that even the magnetic field is
taken into account, we only need some regularity conditions of the density and
velocity as in [27] to ensure the energy conservation.
