he in vitr effect of high enery shock kwave:(HESW) on human peripheral blood lymphocyteswas investigted. The HESW used in the investigation were generated with JT-II lithotripter by un-der spark discharge the results demonstraled that the chromosome of human peripheral blood lympho-cytes was aff ected by HESW .The influence was dependent on the position of the sample to the F2and shock number.