Specific surface area and pore-size distribution of various hydroxyl-alumin-ium cross linked montmorillonites (Al-CLM) with different concentrations ofAl~(3+) ion and OH/Al molar ratios have been studied by double-gas-way chroma-tographic method.The results show that the values of specific surface areasare in the range of 40~180m~2/g. he specific surface area increases with in-creasing OH/Al molar ratio from nearly zero to 2.5 but is essentiallyindependent to the concentration of Al~(3+) ion of the cross li...