Abstarct: Ventilation networks in underground mines may be affected by items such as: locating of objects in air path or destruction of support systems which would result in pressure loss and distortion of air flow. By considering the necessity of keeping the network performances at appropriate level in such conditions, in this study, definition of ventilation network evaluation has been proposed which indicates the network reliability in an uncertain situation. Economic and safety concerns in mines involve this fact that the ventilation network should provide the amount of air in an effective, reliable and safe manner. For designing or evaluating a ventilation network to obtain the devised purposes, designers need criterions and regulations which through them a network with proper performance is achieved. So for, there is no determined approach to analyze the efficiency of network. It seems that calculation of network components reliability and then, at last, estimation of network reliability is the best measure in order to achieve this aim. In this study has been recommended a new method baxsed on Dijkstra algorithm for analysis of the reliability of ventilation network. Whit using of the air flow distribution function that has been created due to train moving in haulage tunnel is defined reliability of each branch network.