The adsorption properties of H-STI and Na-STI, which were prepared from the natural CXN zeolite obtained in China, were investigated with N~2, NH~3, CO~2, ethylene, propylene, water, methanol, ethanol and 1-propanol. The BET surface area and pore volume of H-STI and Na- STI were about 420 m^2/g and 0.20 m^3/g. The adsorption heat of NH~3 and CO~2 on H-STI calculated by the adsorption isotherms at different temperature was 44.8 and 26.5 kJ/mol respectively. The investigation of the adsorption isotherms of ethylene, propylene, methanol, ethanol and 1-propanol on Na-STI reveals the unusual selectivity to the length of the carbon chain in the molecules of organics. The loading of water is lower than that of methanol in lower partial pressure, which exhibits a somewhat hydrophobic property of the zeolite.

Key words: ZEOLITE, ADSORPTION, SELECTIVITY, NITROGEN, AMMONIA, CARBON DIOXIDE, ETHYLENE, PROPENE, WATER, METHANOL