A phosphor material composition for producing blue phosphor by the excitation of UV light and a method for making the same. The phosphor material is an alkaline-earth silicates compound with a chemical formula of A.sub.2-xSiO.sub.4:Ce.sub.x. A includes one or more elements selected from the collection of Ba, Sr and Ca alkaline-earth metals. The host is A.sub.2-xSiO.sub.4 and the activator is Ce.sup.3+. The characteristic of this invention is the blue phosphor material with a high luminescence intensity that can be excited by UV light. In addition, the material in this invention is easy and fast to prepare in a large amount, and the material itself has advantage such as color purity and thermal stability, so as to have a high industrial value.