AbstractThis paper presents spectroscopic, thermal, and morphological properties of two bamboo species viz. Gigantochloa brang and Gigantochloa wrayi. The nature of cell wall structure and distribution of vascular bundles in G. brang and G. wrayi were studied by scanning electron microscopy and transmission electron microscopy techniques. Gigantochloa spp. at various positions and locations showed identical thermal stability and are stable up to 200 °C. The decomposition of cellulose and hemicelluloses component of the culm occurred between 220 °C and 390 °C, while the degradation of lignin takes place above 400 °C.