Abstract: Three polysaccharides, namely AP-1, AP-2, AP-3, which were proved to be homo-geneous by glass fiber paper electrophoresis, ultracentrifugation analysis and gel chromatography, were isolated from the stems of Dendrobium aphyllum. The limiting viscosity numbers of three polysaccharides were 426.96, 416.96 and 234.03 respectively. Their molecular weights (Mw) were 86300, 61500 and 43100 respectively.

Key words: Dendrobium aphyllum