  We study the correlation between CP violation in neutrino oscillations and
leptogenesis in the framework with two heavy Majorana neutrinos and three light
neutrinos. Among three unremovable CP phases, a heavy Majorana phase
contributes to leptogenesis. We show how the heavy Majorana phase contributes
to Jarlskog determinant $J$ as well as neutrinoless double $\beta$ decay by
identifying a low energy CP violating phase which signals the CP violating
phase for leptogenesis. For some specific cases of the Dirac mass term of
neutrinos, a direct relation between lepton number asymmetry and $J$ is
obtained. For the most general case of the framework, we study the effect on $
J $ coming from the phases which are not related to leptogenesis, and also show
how the correlation can be lost in the presence of those phases.
