In this study, non-premixed combustion characteristics and soot formation of methane and various shale gaseous have been investigated in a combustion chamber under lean combustion conditions. After validation of the soot model with published experimental data, the flame characteristics considering flame lengths and diameters, intermediate species, temperatures, and pollutants of shale gaseous have been compared. The findings of this study show that the Moss-Brookes soot model predicts more accurate than the One-Step and Method of Moments models. Since the Methods of Moment method estimates higher soot formation than the experimental method, while the One-Step method estimates lower. The flame characteristics show that although the flame temperatures are close to each other, they differ relatively. In addition, flame lengths, flame reaction zones, and intermediate product concentrations differ similarly, and these differences also emerge as a factor in soot formation. Furthermore, the highest amount of soot is released during the combustion of Barnett shale gas. It is minimal for methane despite emitting intermediate species as much as shale gases. Since more unburned C elements released during the combustion of shale gases. Therefore, when the C/H ratio in hydrocarbon fuels increases, the amount of soot emitted from the flame also increases.