The objective of this work is to study flue gases emission regularity with soot formation in fixed bed. A laboratory-scaled, movable fixed bed has been designed and employed in the process. The results of experiments show that the relative concentration of saturated aliphatic hydrocarbons are decreased by 42.98% and that of aromatic hydrocarbons are increased by 50.84% with temperature increase; the relative concentration of saturated aliphatic hydrocarbons are decreased by 39.05% and that of aromatic hydrocarbons are increased by 30.71% with the residence time extension; more aromatic hydrocarbons are formed in flue gases from high-volatiles coals combustion; and the relative concentration of saturated aliphatic hydrocarbons and aromatic hydrocarbons are decreased with oxygen quantity increase.