The study on soil heavy metal content of apple orchard in gully region of the loess plateau showed that high input and different apple tree ages have an obviously effect on soil heavy metal content and its migration.The soil Cu content increases along with the tree age increases.The input and output of soil Cu tends to be balance when the apple tree have planted more than 20 years

and the Cu content change is very small

and the topsoil Cu content is higher than the other soil layers.The soil Cr content increases progressively along with the tree age in a line

in 0~20 cm

20~40 cm and 40~60 cm soil layer of 36 year orchard

Cr content increased by 27.14%

17.09% and 19.17% compared to the 6 year orchard

respectively.The soil Cd content increased firstly

and then reduced.The main origin of soil Cd is the phospate fertilizer iuput.In deep soil layer of apple orchard

the Cd content peak appears ahead of time than that in the topsoil.Soil Pb content is higher in 15~26 year apple orchard.Take 15 year as a turning point

soil Hg content change present different tendency on the different soil layers.Soil As content reduced when the tree age was little than 15 year

and it increased when the tree age was between 15 year and 20 year

and it changed a little after planted 20 years.The change of As content between soil layers was not significantly.