Next-generation biomaterials are expected to possess both desirable mechanical features and unique biological functions. Recently, two plant-derived glucomannans (GMs)-Konjac glucomannan (KGM) and the polysaccharide of Bletilla striata (BSP)-have emerged as new sources for development of biomaterials. They have been fabricated into drug delivery vehicles and wound healing dressings in varying shapes and sizes, and demonstrated strong gelling properties, high biocompatibility and remarkable convenience for processing and modification. Notably, they demonstrate bioactivities such as response to enzymes produced in special biological niches and/or affinity for carbohydrate receptors on specific cells. All these mechanical and biological advantages suggest these two GMs have great potential for future development and broader application in various biomedical and pharmaceutical fields.