Background. The organs of human body analysed from the viewpoint of security of biological materials have their own biomechanical capacities. Thus, both the daily practice and practical medicine should take into account this fact. The values of physical and mechanical parameters of organs and tissues directly show the content and condition of connective tissue and its functions. As to determining the safety of biological material, the human duodenum, as well as the pylorus are at an incipient phase, which, presently, cannot be told about other anatomical formations. Material and methods. The walls of components of the human duodenum and pylorus have been studied. The material was sampled from 90 persons of both sexes, aged between 22 and 89 years old, whose organs of abdominal cavity were healthy. As many as 540 samples cut longitudinally and transversally and ring-shaped from the anterior wall of duodenum were examined. The values of indicators: breaking point, maximal relative expanding and coefficient of rigidity were set. Results. The values of the above-mentioned parameters were established. Data in figures are presented as tables and also provided with text data. The ring-shaped samples, regardless of their genesis, distinguish by a more increased breaking point against the lamellar samples. Both the maximal relative expanding and Young module vary within more restricted limits compared to breakout force and breaking point of samples. Conclusions. The analysis of breaking and deforming properties of pylorus and wall of components of duodenum in human allowed setting the values of main tensometric indicators (breaking point, maximal relative expanding, coefficient of rigidity) depending on the form of samples (lamellar, ring-shaped), portion of duodenum and direction of action of mechanical force (longitudinally, transversally).