Abstract: Objective: To investigate the extraction technology of hydrophilic components from seaweed,and to analyze the physical properties of the components.Methods: The extraction technology was studied with alkali as catalyst.The major factors affecting the extraction technology of the hydrophlic components from Gelidium amansii were considered,and extraction conditions were optimized by using yield as evaluation index.Results: Six hydrophilic extracts were obtained from seaweed and they had distinct differences in the major properties such as swelling ratio,weight loss and freezing point.Conclusions: The over-all properties of the obtained hydrophilic components from Gelidium amansii were the best of the 6 hydrophilic extracts from seaweed.