  The XMM-Newton Survey Science Center is constructing a large (~1000 sources)
and complete sample of bright serendipitous XMM-Newton sources at high galactic
latitude, so as to allow both the discovery of sources of high individual
interest as well as statistical population studies. The sample, known as ``The
XMM-Newton Bright Serendipitous Source Sample" (XMM-Newton BSS), has a flux
limit of ~10^(-13) cgs in the 0.5--4.5 keV energy band and will be fundamental
in complementing other medium and deep survey programs (having fluxes 10 to 100
times fainter) in order to: a) characterize the X-ray sky and its constituents,
b) understand the evolution of the population selected and c) define
statistical identification procedures to select rare and interesting
populations of X-ray sources (e.g. high z clusters of galaxies, BL Lacs, type 2
QSOs, etc..). We discuss here the scientific rationale and the details of the
project and we present some preliminary results.
