Understanding the effect of glass network structure on the solubility properties of bioactive glasses is fundamental for designing new compositions with tailored biological functions and applications. This paper bridged the composition-structure-property relationship utilizing experimental measurements and molecular dynamics simulations. The Sr atom reorganized the network structures through a partial transformation of tetrahedral to trigonal boron units and the change of the ratio of bridged oxygen/non-bridged oxygen, which modified the glass structures at longer lengths scales, such as through changing the ring size distribution. Our results demonstrated that the evolution of solubility properties can be linked to the atomic structure change in short- and medium-range ordering. The structure-property relationship can be used to design and tune bioactive glass composition with specific properties.