  The neutral Higgs sector of the minimal supersymmetric standard model (MSSM)
in explicit CP violation scenario is investigated at the one-loop level. Within
the context of the effective potential formalism, the masses of the neutral
Higgs bosons are calculated at the one-loop level by taking into account the
contributions of the following loops of ordinary particles and superpartners:
top quark, the scalar top quarks, bottom quark, the scalar bottom quarks, tau
lepton, the scalar tau leptons, $W$ boson, the charged Higgs boson, the
charginos, $Z$ boson, the scalar and pseudoscalar Higgs bosons, and the
neutralinos. Our calculation is an improvement in the sense that both the terms
which are quartic in the electroweak coupling constants into account, and the
pseudoscalar Higgs loop contribution are explicitly included.
