Large quantities of an ascidian, Styela plicata, are harvested annually as the by-product of oyster culture on the south coastal area in Korea. It has been traditionally favored and consumed because of its peculiar taste and flavor. But no study on its taste compounds has been reported. An investigation on the taste compounds of fresh meat and integument of an ascidian has been carried out by a series of analysis of taste compounds including nucleotides, free amino acids, betaine, TMAO, TMA and total creatinine. The most abundant nucleotides in fresh meat were AMP and IMP. Their contents were $1.2;and;0.8{mu}mole/g$, respectively. The contents of nucleotides and their related compounds in integument show similar tendency as in fresh meat but their quantities were very low as compared with those in fresh meat. Seventy two percentage of the total free amino acids in fresh meat was consisted of proline, alanine, glutamic acid, glycine and serine. They occupied also 82% of the total free amino acids in integument, but the amount of free amino acids in integument was about 1/10 of that in fresh meat. The contents of betaine-N and creatinine-N were 6.1 and 2.1% of the extractive-N in fresh meat, respectively. The amounts of TMAO-N and TMA-N were very low contents in fresh meat and trace in integument.