Abstract: The red O-phenanthroline Fe and ⁵⁹Fe was used to study the absorption, transportation and distribution of iron in the apple trees. Fe^{2 +} was absorbed by root and transported to stem, leaves and main vein when iron fertilizer was root injected. Fe^{2 +} was transported along xylem near cambium. The speed of
transportation reached dozens centimeter per hour. Distribution of ⁵⁹ Fe in cutting root and leaves was 19.3% and 70.9% , respectively. The ratio of iron distributed in leaves by cutting the one, two, three roots were 57.9% , 63.6% and 68.0% , respectively. When the trunk was injected with iron fertilizer with high-pressure, Fe^{2 +} was transported along the central xylem, most of Fe^{2 +} was transported to the root and stored in it. The speed of transportation reached several hundreds centimeter per hour. When the trunk was injected
with iron fertilizer, the covery of iron deficiency chlorosis trees was slower and the effect of correcting iron deficiency chlorosis lasted longer than iron fertilizer was root injected. Iron fertilizer could be absorbed and transported by branch and leaves.

Key words: Apple, Iron, Absorption, Transportation, Distribution