Abstract: Abstract Some kinds of soil in Shandong old apple production area are becoming acidified with more and more fertilizer application. In order to evaluate the effects of acidified soil and its modification on fruit quality, some Fuji apple orchards were used to study the effects of acidified soil and some acidified soil modifiers on apple fruit quality and soil characters, and thereby analyze the effects of soil pH on comprehensive fruit quality with statistical modern. The results showed that the relative coefficient between soil pH and fruit single weight, total soluble solid content, soluble sugar content, skin red color (a*) and fruit flavor were 0.9711, 0.9548, 0.9629, 0.984 and 0.9494 respectively，all of which were bigger than r0（r0=0.9500）. It is proposed that orchard soil acidification not only decreases apple yield but also reduces fruit quality. Some new acidified soil modifiers, such as that used in this study with used Bentonite and some organic materials as the main components, were showed to not only increase soil pH value but also improve apple qualities.