Thermal analyses were used to study the loading and the affinity of organic adsorbates on siliceous ferrierite type zeolite, which possesses perfect framework and high hydrophobic character after calcination for removing the template in the as-synthesized form. Twenty organic compounds with various functional groups, i.e., n-butane, n-pentane, n-hexane, n-heptane, methanol, ethanol, 1-propanol, 1-butanol, methylamine, ethylamine, n-propylamine, n-butylamine, formic acid, acetic acid, formaldehyde, acetaldehyde, diethyl ether, acetone, methyl formate, and ethyl formate, were investigated as the adsorbate. The A(T) index, defined as the value of T-desorption -T-bp, was determined and used to compare the affinity of the organic compounds toward the zeolite. Organic molecules containing frameworkphilic functional groups such as alkylamines show high A(T) values. The oxygen-containing frameworkphobic functional groups such as alcohols and organic acids show lower A(T) values. The effect of other functional groups and the chain length of the alkyl group on the affinity are discussed. Compared with the data on high silica MFI and FAU zeolites, the A(T) values exhibit the same tendency for organics with the same functional groups. The influence of pore size and configuration of the zeolites on the A(T) values of various organic compounds adsorbed is discussed.