Abstract: The Ultracytochemical localization of peroxidase during the ground tissue development in bamboo Phyllostachys edulis culm was studied with cytochemical technology. In the primary wall development period, peroxidase concentrated in the intercellular layer near the intercellular space, and then extended to all intercellular layer, and at the same time the peroxisome, endoplasmic reticulum and mitochondria also showed peroxidase activity. After that the distribution of peroxidase appeared in the tonoplast and plasma membrane.In the secondary wall development period, peroxidase activity partially increased in the long cell walls and concentrated in the narrow lamellae，especially in dormancy period. The peroxidase activity in the narrow lamellae of the long cell walls declined gradually with aging, and in nine years old culm there was little peroxidase reactive product both in the long and short cells. The short cell always had higher peroxidase activity than that of the long cell. The cell wall, plasma membrane, transfer vesicles and pits of the short cell had also shown higher peroxidase activity. A relationship between peroxidase and the differentiation of the ground tissue in bamboo culms was also discussed.

Key words: Culm