The structural improvement of tendon implant is running in frame of a research project at our department for 3 years. The main goal is to improve a tendon implant construction which has a tensile stiffness similar to the sound tendon. The tendon implant developed on such way that implant should be able to take over the functions of a sound tendon. To reach this goal firstly the measurement results of tensile stiffness of cadaver tendons were evaluated. The tensile tests of cadaver tendons happened in earlier phase of this research. Beside the aim of enhance the tensile stiffness of the implant was a second request that we need to change the place of maximal mechanical stress from end of implant to inside of the implant. To enhance the mechanical behaviour (tensile stiffness) of implant the type of matrix material along longitudinal and radial directions as well as the length of the fibre in the silicone implant were modified. Improvement of construction was performed by numerical simulation using ANSYS. At first we prepared 2D and 3D geometry models on which the tensile analysis was evaluated. Improvement of the construction was supported by a concentrated spring model also which helped us to check the resultant stiffness of the construction. It was successful to increase the stiffness of the original implant with fibre reinforcing. We reached with the new construction (with one reinforcing fibre) almost half of an average cadaver tendon’s tensile stiffness.