In this paper, the thermal effect in a tubular direct carbon solid oxide fuel cell (DC-SOFC) is studied with a numerical model. After model validation, parametric simulations are carried out to study the effects of operating and structural parameters on the thermal behaviors of DC-SOFCs. It is found that the thermal behaviors of DC-SOFC greatly depends on operating parameters and the temperature field in DC-SOFC is highly non-uniform. The position of peak temperature in the cell is highly dependent on the operating potential. In addition, a smaller distance between the carbon bed and the anode is beneficial for improving the temperature uniformity in the DC-SOFC. The breakdown of heat generation/consumption in DC-SOFC shows that the anode processes contribute the most to the temperature variation in the cell. The results of this study form a solid foundation for better thermal management of DC-SOFC.