The service life of concrete used in acid or salt environments affects the salt resistance of cement and concrete. This project aims to study the change of chemical structure and microstructure of the geopolymer composition under soaking in high concentrations of chloride and sulfate at 50,000 mg/L as the simulated salt solution in this project. Geopolymer consisted of 10%wt ordinary Portland cement (OPC type 1) with the other alternative raw materials which were pozzolanic materials and wastes (fly ash and silica fume). The ion penetration into the geopolymer samples after soaking in the simulation salt solution was determined to understand the salt resistance of geopolymer as compared to ordinary Portland cement. Moreover, this geopolymer showed that the chloride and sulfate penetration into the samples presented significantly lower on the inside of the sample than that of the sample surface as compared to the Portland ordinary cement. In addition, the phases change after the setting of geopolymer in high concentrations of chloride and sulfate solution were studied for understanding the mechanism of salt resistance of geopolymer and for developing the concrete composition for salt resistance in the future.