We have made observations of the 21 cm neutral hydrogen line of the ba
rred spiral galaxy NGC 1398 at two configurations of the Very Large Ar
ray. The structure, dynamics and kinematics of the HI gas are studied
over a spatial resolution range of 15 '' to 60 '', with a velocity res
olution of 25.3 km s(-1). Surface density and radial velocity images a
re presented and the H I surface density is compared with B, V, and I
band photometry. The neutral hydrogen surface density is complex, show
ing a large depleted region in the center of the galaxy. Beyond this,
high-density segmented structure, coincident with the tightly wound op
tical spiral arms, is apparent in the high-resolution images. The cent
ral HI depletion is elongated perpendicular to the optical bar. No bar
structure is observed in neutral hydrogen and there is only a weak as
sociation of H I gas with the optical ring. The gas disk extends well
beyond the optical, to a diameter of more than 10'. The velocity field
is symmetric and well ordered, with only small deviations from circul
ar motion apparent at these resolutions. The rotation curve derived fr
om the lowest spatial resolution data peaks and turns over at a radius
of roughly one-half the total gas radius. We use this rotation curve
to calculate the angular velocity and attempt to determine a pattern s
peed by associating prominent optical features with resonances. Using
the inner optical ring and outer pseudoring(s) as markers of possible
resonances, several models are explored, including one with two patter
n velocities. None are found to be completely satisfactory.