A spintronic theory is developed to study the effect of lattice distortion on the magnetic tunnel junctions (MTJs) consisting of single-crystal barrier and half-metallic electrodes.In the theory,the lattice distortion is described by strain,defect concentration and recovery temperature.All three parameters will modify the periodic scattering potential,and further alter the tunneling magnetoresistance (TMR).The theoretical results show that: (1) the TMR oscillates with all the three parameters;(2) the strain can change the TMR about 30％;(3) the defect concentration will strongly modify the periodic scattering potential,and further change the TMR about 50％;and (4) the recovery temperature has little effect on the periodic scattering potential,and only can change the TMR about 10％.The present work may provide a theoretical foundation to the application of lattice distortion for MTJs consisting of single-crystal barrier and half-metallic electrodes.