Resumo. Studies about lignocellulosic materials have gained importance in the last decades due to the outstanding characteristics that their fibers offer, which becomes in a good alternative to replace synthetic fibers. Lignocellulosic materials such as bamboo have high availability in most of regions around the world due to the adaptation capacity to grow in different areas and diverse climatic conditions. Despite of this fiber has being widely used; their microstructural organization into the culm has not been fully studied. The focus of this research is to study the morphology, distribution and crystalline compounds of fiber in native Colombian Bamboo called Guadua angustifolia Kunth for two varieties Rayada Amarilla and Macana. Scanning electron microscopy was used to observe Guadua fiber morphology and their variation throughout the culm, X-ray diffraction was used to identify crystalline compounds present in Guadua angustifolia Kunth and AOAC-2000 methodology (Association Official Agricultural Chemist) was used to get quantitative information about the insoluble and soluble fiber content into Guadua culm. Findings indicated that the insoluble fiber distribution is not homogenous between the internal and external layer of bamboo culm; the fiber content inside of Guadua angustifolia culms increases from inner to outer layer. X-ray patterns showed that the insoluble fiber has a preferential crystalline orientation in relation to the growth direction of bamboo. The combination of scanning electronic microscope and X-ray diffraction offers important information about the localization and morphologic distribution of components inside bamboo culms.