The serum protein components of flounder, Paralichthys olivaceu were analyzed by capillary zone electrophoresis (CZE). Three kinds of proteins can be analyzed with current experimental conditions. Based on the time that these proteins appeared, they were named as Peak 2.59, Peak 1.60 and Peak 0.77. After storage at room temperature (25℃) for 24 hours, the protein Peak 2.59 remained stable, while the other two proteins were destroyed. Comparison of the results with those of the analysis of human beings serum, the protein Peak 2.59 is probably attributable to Albumin, the protein Peak 1.60 is probably attributable to Globulin-α, the protein Peak 0.77 is probably attributable to Globulin-β.