The kinetic study of Beckmann rearrangement of cyclohexanone oxime catalyzed by trifluoroacetic acid and acetonitrile in a microreactor is presented in this article. Parametric studies are conducted varying temperature, ratio of trifluoroacetic acid to acetonitrile, and concentration of cyclohexanone oxime. The inhibition effect of -caprolactam in this reaction system is firstly reported. A comprehensive mathematic kinetic model considering the product inhibition effect of caprolactam has been developed in the temperature range of 368-391 K, which agrees well with the experimental results across a broad experimental parameter space. In addition, kinetic study indicates that the esterification of cyclohexanone oxime and transposition reaction of the intermediate are both supposed to be the rate-determining steps, and in this catalyst system, the ratio of trifluoroacetic acid and acetonitrile mainly influences the reaction rate and the activation energy of the transposition step. The developed model could provide much reliable knowledge for industrial application. (c) 2017 American Institute of Chemical Engineers AIChE J, 64: 571-577, 2018