  A QCD analysis of jet production in deep-inelastic scattering is presented.
The studies are based on recent measurements of jet cross sections in the H1
experiment at HERA which are directly sensitive to the gluon density in the
proton. The inclusion of H1 data on the inclusive deep-inelastic scattering
cross section enables us to perform a consistent, simultaneous determination of
the quark and gluon densities in the proton. The gluon density has been
determined at fairly large values of $0.01 < x < 0.1$ at a scale of the order
of the transverse jet energies $\mu^2_f = 200\GeV^2$. The result is consistent
with indirect determinations from HERA structure function data and extends
their range of sensitivity to larger $x$-values.

High Energy Physics - Phenomenology