Abstract: We had observed the ultrastructure of cells of cucumber young leaves lacking iron with transmission electron microscopy and had determined changes of some morphology of plant. First the choloroplast structure was broken, and second some mitochondria structure was damaged. The structure of nucleus and endoplasmic reticulum kept intact. After lacking rion for twenty days, most thylakoid of the chloroplast of the young seedlings disintergrated, some cavities appeared in the mitochondrin. Plants were weak. Leaves turned yellow. The contents of chlorophyll were lower.