The effects of mass concentration， temperature， inorganic cation type and pH on the fluid and gelation properties of polysaccharide from Dendrobium officinale(DOP) were evaluated by rheological analysis and FT-IR analysis in this study. The results showed that the DOP aqueous solution exhibited shear-thinning flow behavior under different concentration， temperature， inorganic cation type and solution pH. The viscosity of DOP solution increased with its increasing concentration and the pseudoplastic was more obvious. The viscosity of DOP solution decreased with the increasing of temperature in the range of 5~75 ℃. The addition of Na+ significantly increased the viscosity of DOP solution. However， the viscosity of DOP solution was decreased when K+， Ca2+， Al3+ were added respectively and the change trend was related to the inorganic cation concentration and valence. DOP extracted with hot water had good stability under acidic conditions. However， the viscosity of DOP solution significantly increased under alkaline conditions and the gelation of solution will be occurred under alkaline conditions (pH>10.0). The dynamic rheological results showed that the gel transition was enhanced with the increasing of polysaccharide mass concentration. The FT-IR results indicated that the gelation was related to the absorption peaks at 1 735 cm-1， 2 935 cm-1 and 2 881 cm-1. The above results suggested that the aqueous solution of DOP had unique fluid and gelation properties for processing. The results are useful for the formulation and processing of polysaccharide extracted from Dendrobium officinale.