Juvenile Anoplopoma fimbria (mean length 15.6±1.4 cm, mean weight 68.7±4.3 g) were exposed to 4 months with the different levels of salinity [100 (35.0), 90 (31.5), 80 (28.0), 70 (24.5), 60 (21.0), 50 (17.5), and 40 (14.0) % (psu)] for 4 months. Hematological parameters such as red blood cell (RBC) counts, hematocrit (Ht), and hemoglobin (Hb) concentrations were substantially decreased under salinities of 50% psu or lower. Of the measured inorganic plasma constituents, magnesium was notably decreased, whereas there was no effect on calcium. Among organic plasma components, glucose and cholesterol were significantly increased, and total protein was decreased. Among enzyme plasma components, glutamic oxalate transaminase (GOT), glutamic pyruvate transaminase (GPT), and alkaline phosphatase (ALP) were significantly increased under salinities of 50% psu or lower. Antioxidant responses such as glutathione S-transferase (GST) and glutathione (GSH) were significantly decreased at salinities of 50% psu or lower. The results of this study indicate that salinity affects the blood parameters, plasma constituents, and antioxidant responses of A. fimbria.