Studies on rheological properties of polysaccharide solution from Eucheuma gela-tinae were carried out. A sudden change on the relations of the the shear stress τ vsshear rate D, lgD vs lgτ, D vs η and the thickness index and flowing behavior indexof the polysaccharide solution was observed at temperature 50--60℃.It was found that the slope of the plot line of In n vs 1/τ based on the Arrheniusequation: n = A. e^(v/RT) at the temperature ranges of 30--50℃ was differ from that of60--80℃. It was showed that the flowing activation energy at 30--50℃ was differentfrom 60--80℃, the change of flowing activation energy occurred at 50--60℃.Because of the soddenly reducing on the thickness index of the polysaccaridesolution at 50--60℃ as pointed out above, the application temperature over 50℃ mustbe avoided in using the polysaccharide as a thickner and stablizer.It was found that thickness of the polysaccharide was higher than sodium alginateand partial hydrolytic polyacrylamide (with a hydrolytic degree of 20% and a mole-cular weight of 2.1×10⁵) and the polysaccharide from Eucheuma gelatinae was a goodthickener.