This study was conducted to evaluate whether the nutritional value and palatability of eel soup could be improved by adding green tea during its preparation. Control (E, eel soup) contained catechin 0%, caffeine 0.05%, while eel soup with green tea (GE) contained caffeine 0.25% and 0.53% catechin of which epigallocatechin (EGC) 0.20%, C 0.05%, epicatechin gallate (ECG) 0.28% were investigated. The total phenolic compound content in GE was found to be 112.5 mg gallic acid equivalents (GAE)/g, which is 19.3 times higher than the 5.8 mg GAE/g in E. GE showed high antioxidant activity, with 11.7% and 59.4%. Taurine was extracted with the highest free amino acid content, and the total free amino acid content was 1.46 g/100 g in E and 1.31 g/100 g in GE, which showed that E had a higher free amino acid content. However, the contents of tryptophan, ornithine, and lysine were slightly higher in GE. The results of taste analysis showed that the values for sour, umami, sweet and astringent taste were higher in GE, while those for salty and bitter taste were higher in E. The overall taste value was 32.6 for E and 39.4 for GE, indicating that the overall taste increased with the addition of green tea. Therefore, the addition of green tea during the production of eel soup could be said to contribute to the improvement of the taste and functional nutrition value of the eel soup.