Strain variation on holding under a constant stress was studied in the Ti40,7Hf9,5Ni41,8Cu8 alloy. It was found, that on holding under stress, the isothermal strain rose up to saturation, which value depended on holding temperature and stress. It was found that the dependencies of the isothermal strain on the holding temperature and stress were non-monotonic. This allowed to find the optimal value of stress and time at which the isothermal strain attained the maximum value of 3.2 %. It was found that the maximum isothermal strain in the Ti40,7Hf9,5Ni41,8Cu8 alloy was less than in the Ti40,7Hf9,5Ni44,8Cu5 alloy.