[Problems to be Solved]To provide fluoroaluminosilicate glass powder enabling to improve acid resistance of dental glass ionomor cement and a production method thereof.[Solution]A lanthanum compound eluted in the presence of polycarboxylic acid and water exists only in a surface layer of a fluoroaluminosilicate glass powder. An amount of the fluoroaluminosilicate glass powder is preferably 1 to 5% by weight in terms of oxide. The fluoroaluminosilicate glass powder is produced by mixing an aqueous solution of a lanthanum compound and a fluoroaluminosilicate glass powder not containing lanthanum, and heating them. The aqueous solution of lanthanum compound is an aqueous solution of a water solvable lanthanum compound, preferably an aqueous solution of lanthanum nitrite and/or an aqueous solution of lanthanum chloride.
