ABSTRACT The Lattice energy of a cubic nickel crystal has been calculated by using the embedded atom method. The embedding energy has been determined by means of quantum mechanical approximations. The lattice energy changes of the static structure including 864 atoms with Bain  and shear stresses have been obtained. The energies of the fcc and bcc phases caused by Bain stress have been compared. The variation of the barrier energy required for the transition between these structures has been investigated as a function of shear stress intensity. As a conclusion, we have determined that the barrier energy of fcc→bcc transition rises in shear stress fields.   Key Words: Phase Transition, Barrier Energy, Embedded Atom Method, Stress Fields.