Abstract: In order to design and calculate the various parameters of mine ventilation correctly, optimize ventilation network system, we develop an unsteady simulation calculating system for ventilation network of roadway. The system can be used for complex ventilation network, predicting ventilation parameters including the air volume, temperature, humidity, wind speed, wind resistance in roadway with temporal variation. The characteristic of the system is considered the roadway of seasonal change of climate; wall of roadway is obtained by using the finite difference method for flow heat transfer and temperature distribution within the surrounding rock of roadway. A roadway with heating element network model, the measured data of a mine in natural ventilation conditions with one year seasonal variation is given; all kinds of ventilation parameters and heat extraction rate of a calculating network are calculated, and the validity of the simulation system is evaluated. The developed numerical simulation system is not only suitable for forced ventilation network, but also applies to natural ventilation network simulation calculating.