To provide fluoroaluminosilicate glass powder enabling to improve acid resistance of dental glass ionomer 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 lanthanum compound 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.
