The performance of computational methods and lase diagnostic methods enable us to see the reaction dynamics precisely. Our research group aims to understand the macroscopic phenomena such as ignition and flame propagation in internal combustion engines by using the microscopic information of atoms and molecules with the aid of chemical kinetics modeling. Based on the quantum chemical and chemical kinetics calculations, we are trying to develop the reaction mechanisms of gasoline, diesel fuel, and biofuels those quantitively predict the ignition timing and pollutant formation in internal combustion engines. By using these reaction mechanism, we will propose the innovative combustion technology with the collaboration of other research group at university and automobile company all over the world.