This book presents the results of the study in the field of kinetic and numerical simulation of complex (multistep) chemical reactions. Numerical analysis methods of kinetic models of multistep chemical reactions are elucidated. Also the new value method of computerized study of the kinetic models of reaction systems is proposed which is distinguished by calculation simplicity, clearness, interpretability of obtained results in the terms of physics and chemistry, and in a variety of solved tasks. The given method of investigations is based on the Hamiltonian systematization of reaction mechanisms which reveals the value (kinetic significance) of individual steps and species, and, as a result, determination of the rational ways to control chemical reactions. The value of individual steps and species is determined as a ratio of the response of selected characteristic dynamic magnitude of a chemical reaction system in a certain point of time to the small disturbance of the rate of individual step and the rate-of-production of species accumulation in the initial point of time.