Abstract: The similarities and differences between simulation experiments on thermochemical sulfate reduction (TSR) and geological observations have been compared.Some results of the TSR simulation experiments are consistent with the natural TSR process in terms of products,reaction temperature,catalysts,etc.; however,there is a big gap between current TSR simulation experiments and actual geological process.Owing to relatively simple reactants,limited experimental time as well as comparatively less catalysts,some complex chain reactions during the actual geological processes fail to occur in the TSR simulation experiments,preventing some of the reactions from achieving the extent of reaction under geological conditions.Therefore,the TSR simulation experiments fail to reproduce the phenomena observed under actual geological conditions.Significant differences exist between simulation experiments and geological observations on the sulfur isotopic fractionations of hydrogen sulphide and the carbon isotopic fractionations of n-alkanes.In order to carry forward the study of TSR reaction mechanisms and dynamics and to efficiently figure out TSR-related geological and geochemical issues,the future TSR simulation experiments should use more complex reactants,systems and all kinds of catalysts.