The destruction rate of microorganisms by heat follows the first order reaction. In this experiments, the calculated sterilization velocity constants of Escherichia Coli are 1.97 * $10^{-2}min^{-1}.(45{deg}$ C), 9.53 * $10^{-2}min^{-1}.(55{deg}$ C) and $1.858min^{-1}.(70{deg}$ C), 2.89 * $10^{-2}min^{-1}.(80{deg}$ C), 1.32 * $10^{-1}min^{-1}.(90{deg}$ C), 2.87 * $10^{-1}min^{-1}.(95{deg}$ C), 7.91 * $10^{-1}min^{-1}.(100{deg}$ C) and $1.777min^{-1}.(105{deg}$ C). In the results, the activation energy of E. Coli is 62.0 Cal $mole^{-1}.(45{deg}-60-{deg})$, that of B. Subtilis are 17.8 Cal $mole^{-1}(60{deg}-80{deg}$ C) and 47.1 Cal $mole^{-1}(90{deg}-105{deg}$ C).