Provided is a dielectric/barrier rib composition for a plasma display panel, comprising a compound 1 of the formula ##STR00001## or at least one compound belonging to a polyhedral oligosilsesquioxane (compound 2) having R.sub.6SiO.sub.1.5 as a repeating unit, or comprising inorganic/organic hybrid materials having compounds 1 and 2 as a monomer, wherein X is an integer inclusive 0, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently a linear, branched or cyclic C.sub.1-C.sub.12 hydrocarbon group containing one or more alkyl, alkoxy, ketone, acryl, methacryl, allyl, aromatic, halogen, amino, mercapto, ether, ester, sulfone, nitro, hydroxyl, cyclobutene, carbonyl, carboxyl, alkyd, urethane, vinyl, nitrile, hydrogen, or epoxy functional group, and A is oxygen or NH. The inorganic/organic hybrid materials can be a material composed of an extended matrix, containing silicon and oxygen or nitrogen atoms, and having at least one silicon fraction directly bonded to a substituted or unsubstituted hydrocarbon atom.