Abstract: The addition of paclobutrazol at 0.5 or 2.0 ppm to rooting medium markedly reduced frech and dry weight of shoots, fresh weight of leaves and leaf area, increased leaf weight per area, root fresh and dry weight and root-shoot ratio, and also promoted root formation of apple(Malus pumila) plantlets cultured in vitro. Paclobutrazol increased leaf chlorophyll content on a area basis, but no influence was observed on a weight basis. Compared with the control, the leaves of the treated plantlets showed higher contents of starch, protein, free amino acids and activity of peroxidase, but there was no differences in the contents of soluble sugars.