Abstarct: In the mining industry and production units, in order to achieve the best operating conditions and thereby improving the economic conditions of the project, using of an engineering indicator in the name of reliability will help it.In a mining operating, The volume of investment in mining machinery can affect the entire project. In mining projects, in order to have continuous production, maintain healthy functioning of the machinery is vital. Poor performance of the haulage system in the production cycle of a mining unit, can cause interval or even complete stop of the mining system. Therefore, in this thesis was to evaluate the reliability of the haulage system. haulage system consists of two parts loading and porterage. Loading and porterage systems includes excavator and truck. In the following, during a case study in Torbat Heydarieh Zarmehr gold mine, three excavators and three trucks were studied to assess the reliability of the haulage system. Excavator Includes 4 subsystems mechanical, loading, motion and electrical and Truck Includes 3 subsystems, mechanical, motion and electrical. Then, The Failure data and stops related to loading and porterage systems for this six devices were recorded over a period of six months. The data for analysis of haulage system reliability using Markov, modeling and simulation methods were used. The results of the Marcov method showed that in the case that every six devices is working, reliability of haulage system is about 68.8%. For modeling haulage system reliability, subsystems of excavators and trucks was calculated. After calculating the subsystems reliability, reliability of any device was obtained. Then, loading and porterage subsystems reliability were obtained. Due to the series of loading and porterage units in haulage system, the reliability of the Zarmehr gold mine haulage system was calculated. The results showed that the reliability of the haulage system reach zero after 80 hours. Also using of kamat and riley (K-R) Monte Carlo method, the reliability of the haulage system was simulated. To run the simulation algorithm, a computer program was prepared in Microsoft Visual Studio 2010 software. With this program, reliability simulated curve was drawn and showed, the reliability of haulage system reaches to zero after 80 hours, that is very consistent with the results of modeling but the curve of simulation method have a higher ability to predict the reliability of the haulage system. Finally, using the results of the analysis of reliability, preventive maintenance program has been proposed to improve the performance and reliability of Zarmehr gold mine haulage system.