FIELD: metallurgy. SUBSTANCE: invention relates to the field of studying the processes of martensitic transformations in metals and solid-phase metal alloys and can be used, for example, in research centres or in the technical control departments of metallurgical plants producing titanium and alloys based on it. A method is claimed for determining the critical hardening temperature Tcr in titanium alloys, including determining the chemical composition of the titanium alloy and the polymorphic transformation temperature Tpt, finding the upper limit of the range of Tcr by performing a thermodynamic calculation of changes in the phase composition of the alloy in the temperature range from 600°C to Tpt +(5…50)°C according to the chemical composition of the alloy, checking the adequacy of the calculation by comparing the temperatures Tpt obtained by test hardening and Tpt obtained as a result of thermodynamic calculation, with a difference of less than 10°C, then calculate the change in the value of the molybdenum equivalent from the heating temperature, determine the temperature Tcr0, which corresponds to the value of the molybdenum equivalent of 11 wt.%, heating and hardening are carried out at temperatures Tcr0 - 10°C and Tcr0 - 20°C, the temperature Tcr is determined from the quenching performed as the average value between the two adjacent temperatures at which martensite is and is not found in the structure. EFFECT: increase in the accuracy of the data obtained. 1 cl, 4 dwg, 1 tbl.