We report on a new measurement of di-jet cross section in photoproduction,
using an integrated luminosity of L similar or equal to 7.2 pb(-1) taken wi
th the H1 detector at HERA. A leading order effective parton density of the
photon is deduced, which extends down to small parton fractional energies
of x, = 0.04. This allows a measurement, in a largely unexplored kinematic
domain, of the gluon density in the photon which is compared to QCD-inspire
d models and to a recent H1 measurement using charged tracks.