The invention describes a porous composite material that comprises a porous substrate based on a refractory inorganic oxide in which said substrate has a zeolite crystal content that is less than 25% by mass, whereby said crystals are dispersed homogeneously in the pores of said substrate, and the distribution coefficient that is measured by Castaing microprobe is between 0.75 and 1.25, and in which the total pore volume of said substrate represents at least 40% of the initial total pore volume of the substrate, and the mean diameter of the pores represents at least 50% of the mean diameter of the pores of the initial substrate, its process for preparation and its use as catalyst in the hydrocarbon feedstock conversion reactions.