Fucoidan is a sulfate polysaccharide extracted from brown algae. Fucoidan has various pharmacological properties, such as anti-tumor, anti-mutagenic, anti-inflammatory, antiviral, antioxidant, anti-fibrogenic activity and anti-complementary activities Objective: This study was aimed to explore the effect of fucoidan on biochemical parameters (ALT, AST, GGT, total protein, albumin, globulin) and protein fractions in hepatotoxicity induced by CCl4 in rats. Materials and Methods: The rats used in the study were randomly divided into four groups of 8 rats each: Control group, fucoidan group, fucoidan+CCl4 group and CCl4 group. After 24 hours from the process of an eight-day experiment, blood samples were taken. The analysis of ALT, AST, GGT activities and total protein, albumin, globulin levels were done by an autoanalyser and serum protein fractions (albumin, alpha 1- globulin, alpha 2-globulin beta- globulin, gamma- globulin and A/G ratio) were electrophoretically determined. Results: In the group of fucoidan+CCl4, it was determined that the levels of AST (p<0.001), GGT (p<0.001), total protein (p<0.01), globulin (p<0.01), beta-globulin % (p<0.01), gamma-globulin % (p<0.001) statistically decreased compared to CCl4 group. Conclusion: It can be said that fucoidan has the property of hepatoprotectant by looking to some biochemical parameters and changes in protein fractions that examined in hepatotoxicity induced by CCl4.