Usually, the major factors of heat-balance in an underground railway are heat generation of tram, heat transfer due to flow of air and heat exchange through the wall surface. If there is a junction between tunnel part and open part or part of tunnel is located above the groundwater level, the route is not symmetrical on thermal condition. It would exert influence on each station that the operation of rolling stocks make heat transfer through the calorie absorbed by the metal mass. Accordingly, we propose the heat-balance theory in which the mechanism of temperature and heat flow is analyzed to the equation of Fourier series using frequency response, and solved by the heat-balance equation including heat transfer of rolling stocks.