The bioactive glass is used widely as bone-repairing material due to its excellent bioactivity, biocompatibility and the function for bone restoration, which depended, to a great extent, on the composition, microstructure of the glass and the process conditions. In this study, effect of process conditions (the melting temperature and time) on compositions, microstructure and the properties of bioactive glass was analyzed using EDS, Density measurement, XRD and FTIR techniques. The results indicated that compositions and microstructure changed because of the selective evaporation of constituent and the change in homogeneity of components.The bioactivities of the glasses prepared under different process conditions were characterized by immersing the glass particles in simulated body fluid (SBF) combined with FTIR technique. The results indicated that hydroxyl-carbonate-apatite (HCA) layer formed on the surface of the samples after 24 hours soaking in SBF. A quantitative method was used to compare the bioactivity of samples. It indicated the different preparation processes had influence on the bio-mineralization properties. Then the optimal preparation condition (1450°C, 30min) was obtained.