We discovered the stabilization effect of only 1 wt % Ba on synthesizing Eu2+-doped pure Sr-S-phase(Sr2AlxSi12-x- N16-xOx+2) under a moderate condition and studied their luminescent properties. The excitation band is at UV-vis spectral region which is about 300-370nm, and the emission band at 508-538 nm. The emission wavelength changes from 508 to 538 nm as a function of Eu2+ concentration, and the maximum emission intensity could be obtained with the Eu2+ concentration of 0.2. This phosphor can be the potential candidate for using as the green phosphor for UVLED-based white light.