Abstract: Syngas prepared by catalytic partial oxidation of methane (CPOM) is of importance to increase the application value of the nature gas. The reaction in CPOM is a complex system which involves partial oxidation (main reaction), combustion, reforming reaction, water-gas shift reaction, carbon deposition and so on. The production of syngas from CPOM has been simulated thermodynamically with the advanced process simulator Aspen Plus and HSC Chemistry program. The influences of temperature, pressure, CH₄/O₂ ratio to the conversion rate of CH₄, selectivity to hydrogen and carbon monoxide are discussed. Moreover, the composition of products in thermodynamic equilibrium and carbon deposition reaction are analyzed and discussed. The result of thermodynamic simulation shows that with the increase of reaction temperature and decrease of reaction pressure, the conversion of methane and selectivity to hydrogen and carbon monoxide is on the rise. Quite amount of carbon deposition will be produced in CPOM reaction when the reaction temperature is 300 ℃ and carbon deposition reaches the maximum value at 550 ℃ which will decrease gradually with further increase of reaction temperature. When the reaction temperature is above 900 ℃ , no carbon deposition will be produced.