Abstract：An optical path of a new holographic interferometry technique is developed to measure and represent vertical displacement (vertical amplitude) fringe patterns acquired at different times in one blast. The displacement variations with line charges is studied at different cross sections of the blast region. The test data show that extreme values of vertical displacement，which is caused by P wave，along the perpendicular line of the line charge middle point is three times more than that of other sections in the full field after the detonation. In addition，the extreme displacement values in other directions are caused by Rayleigh wave. The displacement pattern along the axis of the line charge shows an obvious end-effect. The technique represents an important development in analysis of blast induced displacement fields.
