Abstarct: Producing of Ultrafine Grained mextals (UFG) has attracted much attention in the industry and the scientific community due to their superior mechanical properties. One of these methods is equal channel angular pressing (ECAP), which can be repeated many times due to unchangeability of the sample cross section. The aim of this thesis is to study ECAP process for copper-aluminum bimextallic tube with length of 50 mm and outer diameters of 12 and 10 mm, respectively. After some preliminary trial testes, the need for application of backpressure was observed. Therefore, for application of the backpressure in the exit, the necessary tooling was designed and fabricated. The angle between two channels was selected equal to φ=90°. Considering the nature of the tube, to avoid crushing as well as loss of its internal dimensions, Viton rubber- and copper rod -mandrels were inside the tube.The process was performed with Viton rubber and copper rod from ambient to a maximum operating temperature of 150 °C with a backpressure ranging from 50 to 400 MPa. Due to the undesirable results, the process temperature was increased to 200 °C and 250 °C with backpressures of 50, 100 and 200 MPa. Owing to the limited working temperature of the Viton rubber, only the copper rod was used for the later testes ECAP of aluminum-copper bimextallic tubes at temperatures of 200 °C and 250 °C using a backpressure of 50 and 100 MPa, was successfully performed for 3 passes under route BC, in which after each pass, the samples were rotate 90 ° along the longitudinal axis in a same direction and ECAP process was repeated. The effect of process parameters on the microstructure, hardness and wall thickness of the samples were studied. The micro-Vickers hardness test results showed that after three passes of ECAP the hardness of aluminum tube with a value of 40 HV increased by 118% to 87 HV. Similarly, the initial hardness of copper tube 63 HV increased by 106% to 131 HV. Also, Finite element analysis (FEA) using Abaqus software was carried out with Viton rubber- and copper rod -mandrels at ambient temperature. The results obtained were verified to be in good agreement with experimental results.