At present great attention is paid to the study of interdiffusion of titanium with various elements. This was caused by the difficulties in obtaining strong compounds of titanium with metals and alloys acting as a role of coatings in different cases. The significance of speed and peculiarities of the growth of interdiffusion zone enables one to find the thermic region of technological processes providing maximum strength to the compounds between titanium and protective coatings. This article deals with some results of the investigations on interdiffusion of titanium with the elements which form continuous series of solid solutions, for instance with molybdenum, and also with elements having limited solubility in titanium--with nickel, copper, rhodium, and tungsten. The problems of determining the coefficients of interdiffusion were studied by Matano's graphical method as well as by analytical method of Holl. While carrying out investigations on interdiffusion the concentration of components in the diffusion zone was measured on the attenuation of a narrow beam of gamma- radiation.