This report presents applicability of the on-site mechanical iron-mixing treatment of contaminated soils with chlorinated organic compounds. Two types of soils contaminated with chlorinated ethane and/or ethylene were chemically treated with special iron powder E-200. The iron powder E-200 was mechanically mixed with the soils derived from the site A and B in Japan. Following to the mixing process of the soils, the treatment was carried out and controlled in piles on the ground. The soil A, contaminated with 1,1,1-trichloroethane (MCF) and 1,1-dichloroethylene (1,1-DCE), which maximum concentrations were 6.3 mg /l and 0.14 mg /l respectively, were cleaned below the Japanese Environmental Quality Standards for Soil Pollution within 5 days. During the experiment term, 1,1-dichloroethane (1,1-DCA) was detected as a main intermediate for MCF dechlorination. Small amount of the contaminants, however, dispersed from the surface of the pile, most of the contaminants reacted with the E-200 iron. The treatment for cleaning of the soil B contaminated with 0.19 mg /l of cis-1, 2-dichloroethylene (c-DCE) took 21 days, because c-DCE was regarded to be less reactive with the E-200 iron in the soil.