Emanation thermal analysis was applied for the characterization of LaCo(fsa)(2)en-montmorillonite nanocomposites [(fsa)(2)en = N,N＇-bis(3-carboxysalicydene)ethylenediamine], and the results were compared to the data given by thermogravimetry and evolved gas analysis. The emanating rate of Na-montmorillonite increases np to 250 degrees C with the elimination of the intercalated water, and then decreases progressively, however, with a shoulder at about 650 degrees C when the layers are dehydroxylated. On the other hand, the emanating rate of LaCo(fsa)(2)en-montmorillonite increases up to 370 degrees C, i.e,, until the decomposition of the intercalated complex is achieved. Above 450 degrees C, there is a rapid decrease of this rate, with only a slightly remarkable shoulder at about 650 degrees C, The decrease of the emanating rate is characteristic for a decrease of surface area and porosity of the material, indicating that the thermal stability of LaCo(fsa)(2)en-montmorillonite is rather lower than that of Na-montmorillonite.