Recently, liver damage contributes to big percentage of the morbidity and mortality rates worldwide. Excessive intake of alcohol is one of the major causes of liver injury. When liver injury is repeated and becomes chronic, it leads to development of fibrosis and cirrhosis. In the liver, TGF-β is a profibrogenic cytokine, which participates in various critical events cause liver fibrosis. Seahorse (Hippocampus abdominalis) is a common traditional Chinese medicine and has been widely used for centuries. Seahorse has been known to have a variety of bioactivities, such as anti-oxidant, anti-fatigue, and anti-tumor. Peptide is one of the main compounds of seahorse. In this study, we isolated enzymatic hydrolysate from seahorse H. abdominalis by alcalase hydrolysis and investigated the effect of the hydrolysate on liver injury. In the present in vitro studies, the hydrolysate increases cell viability of Chang cells and protects Huh7 cells from ethanol toxicity. In addition, the hydrolysate inhibits TGF-β-induced responses. In vivo studies show that the pretreatment of hydrolysate reduces alcohol-induced increases of serum Glutamic oxaloacetic acid transaminase and Glutamic pyruvate transaminase activities and increases liver weight and body weight. These results suggest that seahorse may have a hepatoprotective effect.