To study the nutritional value of warty sea squirt, Styela clava, which is one kind of urochoda and it has been used as special seafood stuffs by Korean, the seasonal variations of nutrient was investigated. The moisture content was ranged from 83.6% to 86.8% in experimental period. Maximun glycogen content showed up in June (3.7g/100g sample). The protein(N$ imes$6.25) and lipid content varied with glycogen whereas ash content was not changed remarkably, showing 2.8$pm$0.3%. Predominant minerals in edible portion and integuments were sodium, potassium, calcium and magnesium in order. Predominant constitutiional amino acids were asparagine, glutamic acid, taurine, aspartic acid, lysine and glycine and amino acids occupied 50% of the total amino acid. Porportion of nonpolar lipid to total lipid increased from April to early June while polar lipid level decreased. The neutral lipid was composed of triglyceride(59.32%) and free sterol(23.52%), and followed by diglycerides, monoglycerides, esterified sterols and hydrocarbon, free fatty acid. The phospholipid was mainly composed with phosphatidyl choline(49.7%), and phosphatidyl ethanolamine(33.0%). The major fatty acids of the total lipid in warty sea squirt were C20 : 5(17%), C22 : 6(13.76%), C16 : o(13.91%) and C16 : 1(12.52%).