The activity of Lactate dehyderogenase(LDH) in broadbean was enhanced under the treatment by Pb+2,Cd+2,Hg+2 at the concentration of 5.00mg/kg 2.00mg/kg and 0.50 mg/kg respectively ver the concentrations stated above,it went down.using electrophoresis,5 LDH isozymes were presented differentially under treatment by different metal ions at different dosages.Among them,LDH2 was induced by lower concentration of metal ions.LDH4 was sensitive to metal ions and dispeared when `treated with enhanced conce...