Abstract: Because the influence on local ventilation system varies with the location of heat source, in order to make the analysis more comprehensive, in this paper, the heat sources in inclined roadways and in horizontal tunnel are discussed separately. According to the mass conservation equation and the momentum conservation equation, the heat source in the horizontal roadway forms heat resistance and thus has the throttle effect on air flow. According to the natural wind pressure theory, the heat source in inclined roadway would form hot air pressure opposite the inclined roadway direction. Different hot air pressure exerts different effect on air flow in the roadways. In this paper, all the possible results are analyzed. Finally, the corresponding countermeasures based on different impact of heat source on the local ventilation system are proposed.