  We study the role of the coronal magnetic field configuration of an active
region in determining the propagation direction of a coronal mass ejection
(CME). The CME occurred in the active region 11944 (S09W01) near the disk
center on 2014 January 7 and was associated with an X1.2 flare. A new CME
reconstruction procedure based on a polarimetric technique is adopted, which
shows that the CME changed its propagation direction by around 28$^\circ$ in
latitude within 2.5 R$_\odot$ and 43$^\circ$ in longitude within 6.5 R$_\odot$
with respect to the CME source region. This significant non-radial motion is
consistent with the finding of M$\ddot{o}$stl et al. (2015). We use nonlinear
force-free field (NLFFF) and potential field source surface (PFSS)
extrapolation methods to determine the configurations of the coronal magnetic
field. We also calculate the magnetic energy density distributions at different
heights based on the extrapolations. Our results show that the active region
coronal magnetic field has a strong influence on the CME propagation direction.
This is consistent with the "channelling" by the active region coronal magnetic
field itself, rather than deflection by nearby structures. These results
indicate that the active region coronal magnetic field configuration has to be
taken into account in order to determine CME propagation direction correctly.
