  We study the charge ordering behavior under a magnetic field $H$ in the
extended Hubbard model within the coherent potential approximation. At quarter
filling, for small $H$ we find that the relative variation of critical
temperature is quadratic with the coefficient ${\alpha}$ smaller than the one
for conventional spin-Peierls systems. For intermediate field, a melting of the
charge ordering on decreasing temperature under fixed $H$ at various band
filling is found.
