The paper presents a comparative analysis to determine the optimal temperatures and the activation energies for various origin endo-inulinases from Aspergillus niger. The parameters were estimated based on the literature of the activity curves vs. temperature for hydrolysis of inulin. It was assumed that both the hydrolysis reaction process and the deactivation process of endo-inulinase were first-order reactions by the enzyme concentration. A mathematical model describing the effect of temperature on endo-inulinases from Aspergillus niger activity was used. Based on the comparison analysis, values of the activation energies Ea were in the range from 23:53  3:20 kJ/mol to 50:66  3:61 kJ/mol, the deactivation energies Ed were in the range from 88:42  5:03 kJ/mol to 142:87  2:75 kJ/mol and the optimum temperatures Topt were obtained in the range from 317:12  0:83 K to 332:55  0:72 for endo-inulinase A. niger.