This study presents a clean, novel, and highly efficient system for the decomposition of methyl N-phenyl carbamate (MPC) to phenyl isocyanate (PI). MPC conversion of high as 89% and PI selectivity of almost 100% were obtained using chlorobenzene solvent under high pressure without any catalyst. The effects of temperature and time on the conversion of MPC were investigated, and the apparent kinetics model of MPC decomposition reaction was established. Results indicate that the decomposition of MPC is a pseudo-first-order reaction with Arrhenius parameters of E-a = 71.28 kJ/mol and A = 2.74 x 10(5) min(-1), and the model correlated well with experimental data. This study provides not only a new and clean system for the highly efficient production of PI, but also a guide for the design of reactors in the isocyanate industry.