The ultracytochemical localization of ATPase during the rapid height growth stage in Phyllostachys edulis ‘Pachyloen’ culms was studied with cytochemical technology. The development of internode elongation can be divided into four stages: meristematic stage, initial elongation stage, rapid elongation stage and maturity stage. The results showed that the plasma membrane, karyotheca, organelle membrane system all had high ATPase activity at the meristematic stage. During the initial elongation stage, the plasma membrane of the ground tissue had high ATPase activity in the upper part of the internode, while the short parenchyma cells had higher ATPase activity. There is no ATPase deposition in any cells of the basic part of internode. During the rapid elongation stage, ATPase activity of ground tissue in the basic part of internode was higher than that in the upper part, where the plasma membrane, transport vesicle, intercellular space and plasmodesma all had ATPase activity. Only the plasma membrane of ground tissue in the upper part of internode had low ATPase activity during the maturity stage. During the elongation growth of internode, ATPase was mainly related with synthesis and transport of new cell wall materials, while ATPase around the crystals and starch grains outer membrane played a role in storing materials. At the basic part of internode which had no diaphragm, ATPase activity was not observed, while phloem ganglion had high ATPase activity in the node. The changes of the structure related to mass transport between internode and node were caused by the loss of diaphragm, furthermore influenced internode elongation.