This paper reports the thermokinetic models of single-substrate, enzyme-catalyzed reactions occurring in batch and plug-flow reactors, respectively. By analyzing the calorimetric curves of these reactions, these models can be used to produce not only the thermodynamic data (Δ r H m ) but also the kinetic data (K m and K 2 ). Using a LKB-2107 batch microcalorimeter and an LKB-2277 Bioactivity Monitor, the catalase-catalyzed decomposition of hydrogen peroxide was studied and its molar reaction enthalpy (Δ r H m ) measured as -88.88±0.6 kJ mol - 1 . The Michaelis constant (K m ) for H 2 O 2 was determined by the batch and plug-flow thermokinetic models to be 5.03±0.18 10 - 3 mol dm - 3 and (5.27±0.11) 10 - 3 mol dm - 3 , respectively. The reliability of these models for determination of the thermokinetics of single-substrate, enzyme-catalyzed reactions occurring in these two types of reactors was verified by the experimental results.