An influence of relaxation processes occurred on holding of the Ti50Ni50 alloy at a high temperature on the accumulation of the reversible and irreversible strain on cooling and heating of the sample under a constant stress of 50MPa through a temperature range of the martensitic transformation was studied. It was found that a holding of the sample at temperatures which were higher than Af temperature (finish temperature of the reverse transformation) led to an increase in reversible strain and influenced in a different way on an irreversible strain accumulated in the sample after holding. If a holding temperature was less than 160 oC, then an increase in holding duration resulted in a decrease in irreversible strain accumulated in the sample on cooling under a stress of 50 MPa. If the holding temperature was equal to 160 oC than the holding of the sample did not influence the irreversible strain. In the case of the holding temperature was larger than 160 oC, the irreversible strain increased on a rise in a holding duration. It was assumed that a difference in dependences of the irreversible stain on the holding duration observed at different holding temperature was due to relaxation was a thermally activated process and its intensity depended on a holding temperature.