  We study the relativistic quark-antiquark system embedded in magnetic field
(MF). The Hamiltonian containing confinement, color Coulomb and spin-spin
interaction is derived. We analytically follow the evolution of the lowest
neutral meson state as a function of MF strength. Calculating the color Coulomb
energy $V_{Coul}$ we have observed the unbounded negative (at least in the
limit of large $N_c$) contribution at large MF which makes the mass negative
for $eB> eB^{QCD}_{crit}$. We display the $\pi^0$ and $\rho^0$ masses as
functions of MF in comparison with recent lattice data.
