-The thermal stability of the extracellular fructosyltransferase (FTase) from Rhodotorula sp., recovered from cultivation medium by ethanol precipitation and immobilized onto niobium ore, was studied by Arrhenius plot, half-life profile, half-inactivation temperature (T 50 ) and thermodynamic parameters. The Arrhenius plot showed two different behaviors with different deactivation energies (E ad ) only after immobilization, the transition occurring in the temperature interval between 51 and 52°C. T 50 for the free enzyme was estimated to be around 62°C and, after immobilization, 66°C. After 15 minutes at 52°C, it was also possible to observe enzymatic activation for both the free and immobilized forms, but greater activation was achieved at pH 4.5 with the immobilized enzyme. Between 47-51°C the immobilized enzyme was more stable than the free enzyme, with pH 6.0 being the more stable condition for the immobilized enzyme. However, above 52°C the free form was more stable.