Phenanthrene-induced changes in blood organic components. transaminase and ALP activities of Paralichthys oIivaceus were investigaled. The aim of this study was to obtain a holistic view of the toxic responses, and compensations of fish exposed to waterborne phenanthrene. Fish were exposed to 0, 0.5, 1, 2$mu$M of phenanthrene for 4 weeks. The most noticeable changes were concentration-dependent increase in levels of blood GOT and GPT activities. At concentrations 1.0 and 2.0 $mu$M of phenanthrene GOT, GPT and ALP enzyme activities in plasma were increased. Plasma albumin concentration was stable in phenanthrene-exposed fish, however, plasma total protein level was reduced significantly at the 4-week sampling points (2.0$mu$M). Plasma glucose levels were found to be increased significantly over the cootrol throughout duration of the experiment with phenanthrene. Overall the results suggest that phenanthrene has the potential to alter some physiological functions in olive flounder.