  We study the correlation between the quark spin and orbital angular momentum
inside the pion meson. Similar to the case inside the nucleon, the longitudinal
spin-orbit correlation $C_z^{q/\pi}$ in pion meson can be expressed in terms of
the corresponding generalized parton distributions (GPDs) and generalized
transverse momentum distributions (GTMDs). This provides new information about
the spin structure of the pion. Using the wavefunctions of the pion in the
light-cone quark model and the overlap representation for GPDs and GTMDs, we
present the analytical results for the quark longitudinal spin-orbit
correlation. We find that the GPD approach and the GTMD approach lead to the
same results. The numerical results is also obtained, showing that the
correlation in pion is anti-aligned. In addition, we compare $C_z^{q/\pi}$ from
the GPD approach and the GTMD approach, with $x$ and the transverse momentum
$k_T$ unintegrated.
