In this graduation thesis it is deduced deformation and tightness of leg’s receiver as well as skin and soft tissues’ at contact place. By using the finite elements method with digital ANSYS 5.5.1 programmable packet it was made leg��s prothesis receiver and stump soft tissues’ model. Two models were analysed: linear and non-linear. By making the non-linear system calculation it is measured non-linear features of leg’s prothesis receiver material and stump skin soft tissues’. Results of analyses showed that the size of maximum deformation is 1,3 less then in case of linear system, maximum stress decreases 1,2 times. Consequently for exact contact calculation it is needed to use non-linear model.