In order to comprehensively evaluate the characteristics of heavy metal pollution of electrolytic manganese residue and the harm caused by arbitrary discarding on the growth of surrounding plants. The heavy metal elements, content and manganese morphology of slag-like samples were analyzed with the manganese slag of an electrolytic manganese in Songtao of Guizhou province. At the same time, it was studied that electrolytic manganese residue, leachate and leaching residue effect on the germination potential, germination rate, root length, bud length, fresh weight, dry weight, germination index and vigor index of Chinese cabbage, rape, ryegrass and alfalfa seeds in laboratory. The results showed that the heavy metals of electrolytic manganese slag and its leaching solution were mainly Mn, 28 000 mg?kg-1, 82.00 mg?L-1 respectively. The inhibitory effect of electrolytic manganese residue and leaching solution on plant root elongation was significantly greater than that on seed germination, and the inhibition rate of root elongation is over 42.5% ,even up to 100.0%.