  We investigate chiral symmetry breaking and strong CP violation effects on
the phase diagram of strongly interacting matter in presence of a constant
magnetic field. The effect of magnetic field and strong CP violating term on
the phase structure at finite temperature and density is studied within a three
flavor Nambu-Jona-Lasinio (NJL) model including the Kobayashi-Maskawa-t'Hooft
(KMT) determinant term. This is investigated using an explicit variational
ansatz for ground state with quark anti-quark pairs leading to condensates both
in scalar and pseudoscalar channels. Magnetic field enhances the condensate in
both the channels. Inverse magnetic catalysis for CP transition at finite
chemical potential is seen for zero temperature and for small magnetic fields.
