The present invention provides the composition of an alkali-free glass composition containing no alkali metal oxide and the preparation thereof. The alkali-free glass comprising substantially no alkali metal oxide according to the present invention comprises 61 to 73 wt % of SiO2; 0.5 to 3.9 wt % of B2O3; 3.5 to 13.5 wt % of Al2O3; 9 to 13 wt % of MgO; 1 to 8 wt % of CaO; and 4 to 10 wt % of SrO, based on the total weight of oxides present therein.