Abstract: In order to know the characteristic of orchard soil acidification in the area of east Shandong province, some soil samples were analysed. The results showed that the orchard soil acidification was very strong, soil pH value of orchard was far lower than the value of soil survey in 1981 and that in farmland, and the pH and potential acidity of top soil in orchard was lower than that of subsoil. The cause of orchard soil acidification in the area of east Shandong province focused on the increasing input of chemical fertilizer, decreasing input of organic fertilizer and flooding irrigation.