Abstract: A method of stabilizing thrombin in a thrombin solution is provided. The method comprises heating the thrombin solution at a temperature of 35-85° C. for 1 to 20 seconds, and quenching the heating. Also provided is a stabilized thrombin composition. The stabilized thrombin composition is characterized in that it is prepared by heating a thrombin solution at a temperature of 35-85° C. for 1 to 20 seconds, and quenching the heating. The thrombin solution may be further lyophilized to obtain a stabilized thrombin composition in lyophilized form.