This study was conducted to investigate the major chemical components of dried Capsosiphon fulvescens. The proximate compositions of C. fulvescens as dry matter basis were the moisture content 6.27%, 27.66% of crude protein, 1.68% of crude fat, 10.69% of crude ash, and 53.70% of carbohydrate, respectively. Analysing total amino acids, 17 kinds of components isolated from C. fulvescens. The essential amino acid contained in C. fulvescens accounted for 42.33% of total amino acid, while the non-essential amino acid accounted for 57.67%. Fatty acids were of 13.34% of saturated fatty acids, 21.69% of monounsaturated fatty acids and 64.97% of polyunsaturated fatty acids. Linoleic acid, oleic acid, palmitic acid and linolenic acid were the major fatty acids among 14 fatty acids detected in dried C. fulvescens. Oxalic acid was the major organic acids. The contents of vitamin A and vitamin E were 0.021 mg% and 0.001 mg%, respectively. The mineral contents of dried C. fulvescens were greater in order of Mg<Na<K<Fe<Zn<Mn<Cu. These results suggest that C. fulvescens are able to recommend as a vegetable of highly nutritional quality.