Abstract: The thermal decomposition of hydrogen sulfide to generate hydrogen is a novel control approach for hydrogen sulfide pollution. In this work, the kinetic of thermal decomposition of hydrogen sulfide was investigated. The decomposition efficiency of hydrogen sulfide under various temperature and residual time was studied by using thermodynamics analysis and experiments. The results show that the reacting mechanism proposed fits the thermal decomposition reaction of hydrogen sulfide well. The thermal decomposition of hydrogen sulfide greatly relies on the reacting temperature, and under higher temperature conditions the higher hydrogen generating efficiency can be achieved. When the temperature is low, the reaction time is the key factor to influence the thermal decomposition. The initial hydrogen sulfide concentration has a great influence on the thermal decomposition efficiency, and lower hydrogen sulfide concentration results in a higher thermal decomposition efficiency.