The urgency of the discussed issue is caused by the need to work out new types of industrial intravascular implants from nickel-titanium based alloys. The main aim of the study: analysing a structurally-phase state and characteristics of the martensitic transformations effect in medical nickel-titanium based alloys to implementation of superelasticity effect and by the example of a concrete alloy to determine experimentally an optimum regime of its heat treatment for the directed regulating of the structurally-phase state providing high extent of shape recovery as a result of superelasticity effect. The methods used in the study: thermal resistivity measurements to determine martensite transformation temperatures; torsion deformation method by an inverted torsion pendulum with loading and unloading of samples for measurements of the superelasticity effect and shape recovery parameter. The results: The authors have analyzed the conditions of effect superelasticity developing in nickel-titanium based alloys by martensitic transformations; determined the magnitude and temperature intervals of developing superelasticity effect, shape restoration extent, required for using nickel-titanium based alloys as the materials for manufacturing intravascular implants. It is shown, that for medical nickel-titanium based alloys the required characteristics of implants are attained at heat treatment for implant shape assignment during 15…30 minutes at (500±10) °С.