The heat supply for the circulating air in tunnel driers of partial recirculatingwaste moist gas comprises of four heat comsumptions. (i. e. the sensible heat of exhaustgas, heat of evaporation, heat of elevation of materials and transport equipments, andthe heat loss during drying process). The temperature (t_c) and humidity (x₀) of mixinggas are calculated by means of corresponding equations with clear conception. The following suggestions are consulted with the aid of mathematical treatment: 1. The total heat supply calculated with other different methods can also be sum-marized into four similar terms. 2. The sensible heat and heat of evaporization either with dry or wet base are pro-ved to be perfectly identical with the real case. 3. The values obtained for the properties of air mixture from the tunnel drier bothby I-X chart and by calculation are in close agreements. 4. The choice of parameters of drying medium is considerably important in dryingprocesses design. Acompanying the velocity of drying medium, the teperature (t₂) andhumidity (x₂) of the exhaust moist gas are suggested as basic parameters.