It is an important problem for a new comprehensive utilization technology of oil shale how to obtain both shale oil with a high yield and shale char with good combustion properties referring to ignition mechanism, pyrolysis, and pore structure. In this present work, pyrolysis experiments of 14 shale chars obtained by retorting oil shale under different conditions were performed in a thermogravimetric analyzer; organic matter within these shale chars was extracted by an acetone/hexane mixture solvent and identified using a gas chromatography/mass spectrometry method, and then the effects of four retorting factors (retort temperature, residence time, particle size, and heating rate) were discussed on the pyrolysis characteristics of shale chars. The pyrolysis history of shale chars formed by retorting different oil shales at a retort temperature of 520 degrees C is very similar below the pyrolysis temperature of 660 degrees C, and above 660 degrees C there exist different mass losses attributed to large decomposition of carbonates and organic matter containing amide groups. Either increasing retort temperature from 430 to 460 degrees C or prolonging residence time at a retort temperature of 430 degrees C can obviously decrease mass loss of shale char in the low-temperature stage of pyrolysis and, however, have little influence on the pyrolysis history of all the samples including oil shale in the high-temperature stage. In this study particle size and heating rate show little effect on the pyrolysis of shale char. As a result, for achieving high shale oil yield, good combustion characteristics of shale char, and minimum energy loss during retorting, it is more important to optimize both retort temperature and residence time.