Biodegradable microcapsules entrapping an inorganic salt as a core material are prepared by the solvent evaporation method in the (W/O/W) emulsion system. The effects of the microcapsule preparation conditions on the microcapsule morphologies and the entrapment efficiency of an inorganic salt are investigated. The entrapment efficiency of inorganic salts into the microcapsules is improved by increasing the salt concentration, changing the type of salt in the outer aqueous phase, decreasing the concentration of the core material, and lowering the volume fraction of the dispersed droplets and changing the type of dispersion stabilizer. Especially, it is proven that a very high entrapment efficiency is obtained when gum arabic is used as the dispersion stabilizer.