  For flavor neutrino masses M^{PDG}_{ij} (i,j=e,mu,tau) compatible with the
phase convention defined by Particle Data Group (PDG), if neutrino mixings are
controlled by small corrections to those with sin(theta_{13})=0 denoted by
sin(theta_{13})deltaM^{PDG}_{e tau} and sin(theta_{13})deltaM^{PDG}_{tau tau},
CP-violating Dirac phase delta{CP} is calculated by using these corrections. If
possible neutrino mass hierarchies are taken into account, the main source of
delta{CP} turns out to be deltaM_{e tau}^{PDG} except for the inverted mass
hierarchy with {m}_1 approx -{m}_2, where {m}_i=m_ie^{-i varphi_i} (i=1,2)
stands for a neutrino mass m_i accompanied by a Majorana phase varphi_i for
varphi_{1,2,3} giving two CP-violating Majorana phases. We can further derive
that delta_{CP} approx arg(M_{e mu}^{PDG})-arg(M_{mu mu}^{PDG}) with arg (M_{e
mu}^{PDG}) approx arg(M_{e tau}^{PDG}) for the normal mass hierarchy and
delta_{CP} approx arg(M_{ee}^{PDG})-arg(M_{e tau}^{PDG})+pi for the inverted
mass hierarchy with {m}_1 approx {m}_2. For specific flavor neutrino masses
M_{ij} whose phases arise from M_{e mu,e tau,tau tau}, these phases can be
connected with arg(M_{ij}^{PDG}) (i,j=e,mu,tau). As a result, numerical
analysis suggests that Dirac CP-violation becomes maximal as |arg(M_{e mu})|
approaches to pi/2 for the inverted mass hierarchy with {m}_1 approx {m}_2 and
for the degenerate mass pattern satisfying the inverted mass ordering and that
Majorana CP-violation becomes maximal as |arg(M_{tau tau})| approaches to its
maximal value around 0.5 for the normal mass hierarchy. Alternative
CP-violation induced by three CP-violating Dirac phases is compared with the
conventional one induced by delta{CP} and two CP-violating Majorana phases.
