Abstract: In this paper the main nutritional components and polysaccharid composition of the Gracilaria lemaneiformis collected from the Nanao sea area were analyzed. The results showed that the contents of the crude protein, carbohydrate, crude fat, crude fiber and ash from the Gracilaria lemaneiformis were 19.14%, 43.76%, 0.5%, 4.8% and 28.77% respectively. The Gracilaria lemaneiformis also had a high content of eight essential amino acids and taurine together with essential microelements such as iron and zinc. The content of polysaccharide from Gracilaria lemaneiformis is 31.05%; The polysaccharide extracted by hot water was isolated by DEAE- celluose column chromatography. Three polysaccharide fractions were obtained by eluting with different concentrations of NaCl solutions. The chemistry analysis, paper chromatography and infrared spectroscopy method all showed that polysaccharide from Gracilaria lemaneiformis was polysaccharide sulfate which was mainly composed of D- galactose and 3,6-AG-L-galactose. To every fraction, the contents of SO4- and 3,6-AG-L-galactose had great discrepancy. The polysaccharide eluted by low concentration NaCl solutions was mainly composed of D-galactos(55.8%),3,6-AG-L-galactosee (42.1%) and sulfate-(9.12%).

Key words: Gracilaria lemaneiformis, nutritional components, polysaccharide 2