Abstarct: One of the most important components of the turbine is axial turbine that its task is power generation. The gas turbine is used in power plants in aircraft engines. Since, output stream from the combustion chamber, depends on kind of combustion chamber and its operating conditions, in different operation conditions, the turbine inlet flow will change. Over a period of time in general practice, Turbo-machines preliminary operation, it will be changed؛ also Turbines are no exception. During the operation, due to factors such as entry of dust into the turbine, the impurities in the fuel, chemical reactions with sulfur contamination in the air or fuel that produced by incomplete combustion of unburned carbon, the turbine blades surface can be rough. Quantitative analysis of the effect of roughness on turbine performance is very important. Due to the complexity of the flow into the turbine to know flow and temperature field into the floor of the turbine and calculating roughness effects, three-dimensional analysis is required. Nowadays, with the development of numerical methods for calculations and increase in computational power of computers, we can do fully three-dimensional analysis the flow into the turbo-machines. In this project, a two-stage axial turbine, manufactured by General Electric and Institution NASA, , has been studied. At first this turbine is modeled with software CATIA and BLADE GENERATION and then is used TURBO GRID software for grid generation. Then by using the software ANSYS CFX, fully numerical flow field just without any simplifications on governing equations are made. The solution baxsed on the software's finite volume method. To validate the analysis, the results of the simulation, were compared with the experimental results of laboratory testing of the turbine thrust two stage E3. After validating the used numerical method, which represents the performance of the turbine, the turbine maps is achieved in the form that it work in high-temperature and with gases from combustion products.The given results include the distribution of pressure, temperature, density, Mach number, and flow lines and . . ., In mean surface, or in sensitive areas. The results showed that the total pressure in axial turbine rotor due to energy transfer from the fluid, decreases. Flow velocity increase through the stator blades and rotor blades crossing over is reduced. Then, we study about roughness effects with applying real roughness on stator and rotor blades of the turbine we find its effect on turbine maps. Then we change the geometry due to deposition and erosion and it is discussed. The ultimate goal of all defects on turbine takes place.