Abstract: In this paper, the rezoning technique for Lagrangian meshes is discussed with equidistant principle. A Rezoning threshold value η and fourstep rezoning methed are applied. According to volume ratio, the concerned parameters of meshes between new and old one are redistributed conservatively. The numerical tests show that in order to improve the effect of rezone, not only the position of inner mesh points but also the position of bourdary points are needed to be readjusted.