The soil contaminated with heavy metal is an increasing environmental problem, and distributes inside or around industrial complex, abandoned mines. and shooting fields. When the heavy metal components in the contaminated soil are ionized, they are able to spread through underground water. The heavy metal component should be treated. It was reported that washing process by acid, a conventional method for treating the heavy metal contaminated soil, made the situation worse because the acid solution remove a passivated layer on the heavy metal component. In the present study, leaching of lead was investigated for treating Pb contaminated soil.