Alkali-earth-metaphosphate-based fluoro-sulfo-phosphate M(PO3)(2)-AlF3-MSO4 (MPFS, M = Ca, Sr, Ba) glasses have been developed via simultaneously incorporating fluoride and sulfate into metaphosphate glass. Their glass-forming regions were efficiently determined under the guidance of thermodynamic calculation method. The physical and structural properties of BaPFS glass were investigated in detail. Furthermore, near-infrared spectroscopic properties of Er3+-doped BaPFS (Er-BaPFS) glass were studied. Physical parameters, such as Abbe's number nu(d) (55-75) and nonlinear refractive index n(2) (1.17-1.86 x 10(-13) esu), of BaPFS glass are strongly depended on P/F/S ratio. The structure of BaPFS glass gradually depolymerizes and tends to become multianionic when Ba(PO3)(2) is substituted by AlF3 and BaSO4. Anion-substitution strategy effectively modulates the property and structure of glass, providing a scheme to derive glass materials. In addition, enhanced emission at similar to 1.5 mu m has been observed from Er-BaPFS glass along with large emission cross section (5.0-5.5 x 10(-21) cm(2)) and long lifetime (6.7-7.3 ms), resulting in large figure of merit (3.46-3.84 x 10(-23) cm(2)center dot s), which is a promising candidate for solid-state laser.