  We report on a study of jet shapes in inclusive jet production in $p \bar{p}$
collisions at $\sqrt{s} = 1.96 {\rm TeV}$ using the upgraded Collider Detector
at Fermilab in Run II (CDF II) based on an integrated luminosity of $170 \rm
pb^{-1}$. Measurements are carried out on jets with rapidity $0.1 < |Y^{\rm
jet}| < 0.7$ and transverse momentum 37 GeV/c $< P_T^{\rm jet} < 380$ GeV/c.
The jets have been corrected to the hadron level. The measured jet shapes are
compared to leading-order QCD parton-shower Monte Carlo predictions as
implemented in the PYTHIA and HERWIG programs. PYTHIA, tuned to describe the
underlying event as measured in CDF Run I, provides a better description of the
measured jet shapes than does PYTHIA or HERWIG with their default parameters.
