  We study the generation of the matter-antimatter asymmetry during bosonic
preheating, focusing on the sources of the asymmetry. If the asymmetry appears
in the multiplication factor of the resonant particle production, the
matter-antimatter ratio will grow during preheating. On the other hand, if the
asymmetry does not grow during preheating, one has to find out another reason.
We consider several scenarios for the asymmetric preheating to distinguish the
sources of the asymmetry. We also discuss a new baryogenesis scenario, in which
the asymmetry is generated without introducing neither loop corrections nor
rotation of a field.
