  Pulsars provide unique probes for the {\it large-scale} interstellar magnetic
field in the Galactic disk. The Parkes multibeam pulsar survey has discovered
many distant pulsars which enables us for the first time to explore the
magnetic field in most of the nearby half of the Galactic disk. The fields are
found to be {\it coherent in direction} over a linear scale of $\sim 10$ kpc
between the Carina-Sagittarius and Crux-Scutum arms from $l\sim45\degr$ to
$l\sim305\degr$. The coherent spiral structures and field direction reversals,
including the newly determined counterclockwise field near the Norma arm, are
consistent with bi-symmetric spiral model for the disk field. However, the
antisymmetric rotation measure sky from the Galactic halo and the dipole field
in the Galactic center suggest that the A0 dynamo is operating there.
