Abstract: A natural bamboo possesses excellent mechanical properties due to its special structure. With help of observing and measuring instrument,this paper gained the relationship between the thickness of culm wall of bamboo and the equivalent radius,determined the volume percentage of the vascular bundle,the diameter and average distance of the vascular bundle along the radical direction of the bamboo tube. A model was proposed to describe the distribution of the vascular bundle in radial direction.

Key words: bamboo, vascular bundle, radical distribution, mathematical model