The effect of unbanlance between iron and manganese on Phytolacca acinosa Roxb.root exudates were investigated with hydroponics under eight experimental group(Fe0Mn-,Fe0Mn ,Fe-Mn0,Fe-Mn-,Fe-Mn ,Fe Mn0,Fe Mn-,Fe Mn ) and one control group(Fe0Mn0).The soluble sugar,amino acid,pH value and membrane permeability of root exudates were determinated.The results were showed as follows: The soluble sugar content of Fe-Mn-was a little more than control,but the others were less than control,and thoese of Fe0Mn and Fe Mn reached significant level.The amino acid content of most of treatments was higher than control,Fe-Mn0 was most and showed significant difference to control.The pH values of all of treatments significantly increased except Fe0Mn ,the increasing rate of Fe Mn0,Fe Mn ,Fe Mn-were biggest.what's more,they made the membrane permeability of root increase.In all,both deficiency and overdose of iron and manganese resulted in changing of root exudates,and the effection of iron stress and manganese toxicity was bigger.In addition,compared to individual iron or manganese treatment,root exudates were also affeced by interaction of iron and manganese.