Abstarct: Ventilation design is essential for underground excavations such as mines. There are several perspectives for designing of mines ventilation baxsed on fluids analysis and design method. Ventilation design baxsed on fluids analysis is analyzed in two models of incompressibility and compressibility. Also baxsed on design method has been presented two methods manual and computerize. Air is considered as the main fluid in ventilation design of mines. The important characteristics of this fluid are temperature and its density. baxsed on this, air fluid could be analyzed in two models of incompressibility and compressibility. In the incompressibility model, the values of air temperature and its density remain constant in length of excavation. But in the compressibility model, these values are variable. One of the methods of mine ventilation design in incompressibility model is computerize method. The computerize method is baxsed on approximate mathematical methods. A number of approximate mathematical methods include Hardy Cross method, Wang model of Hardy Cross, spatial model of Hardy Cross, conflation model of Hardy Cross, Newtonian models of Hardy Cross, Wang model of Newton- Raphson and Newton- Raphson with variable directions. Faster convergence to the final answer is one of the main purposes of the above methods. Accordingly, in this research, the above methods are investigated in different models of ventilation networks baxsed on faster convergence to the final answer and the results show that the conflation model of the Hardy Cross and the Newton-Raphson with variable directions are more reliable. Therefore, in this research, for converge faster to the final answer baxsed on conflation model of Hardy Cross method is presented a new method as the second conflation Hardy Cross method. Also, in this research, for easier using of the Newton-Raphson method with variable directions is presented a new method as the Newton-Raphson method without derivative. Also, this research shows that Newtonian's methods have weaknesses for ventilation networks with ventilators that their pressure is certain. baxsed on this, three modified Newtonian methods are presented in this research. For designing ventilation of mines in compressibility model is analyzed air fluid in two models of dry and wet. Due to changes in temperature and density of air in length of excavation, the expressed equations in compressibility model are related to the interpretation of the outlet air characteristics such as temperature, specific gravity, velocity, pressure and humidity in per length of excavation. For interpreting of the dry air model should be solved a nonlinear equation. baxsed on mathematical science is easily calculated its final answer. But For interpreting of the wet air model should be solved two nonlinear equations. For solving these equations are proposed approximate mathematical methods. Accordingly, in this research is presented three new methods for easier interpreting of compressible model. Their names are delta method, K method and K-W method. In delta and K methods are assumed vaporization rate of water vapor is certain. But in K-W method is assumed vaporization rate is uncertain. Also, in this research for reducing errors and increase the accuracy of calculations in mine ventilation design in two models of incompressibility and compressibility is presented a computer program under Windows with name’s “Ventilation Design” in environment of Visual C++ 6.