  We present the first results of the Hubble Space Telescope/Faint Object
Camera long-slit spectroscopy of the inner 8" of the Narrow Line Region of NGC
4151 at a spatial resolution of 0".029. The emission gas is characterized by an
underlying general orderly behaviour, consistent with galactic rotation, over
which are superposed kinematically distinct and strongly localized emission
structures. High velocity components shifted up to ~ 1500 km/s from the
systemic velocity are seen, associated with individual clouds located
preferentially along the edges of the radio knots. Off-nuclear blue continuum
emission is also observed, associated with the brightest emission line clouds.
Emission line ratios like [NeIII]3869/[OII]3727, and [OII]3727/Hbeta are
observed to vary substantially between individual clouds. We advance the
general picture that, as in other Seyfert galaxies observed with HST (e.g., NGC
1068, Mrk 573), the interaction of the radio jet with the ambient gas strongly
influences both the morphology and the physical conditions of the NLR.
