The aim of this study was to determine the effects of Plantago major's (P.major) water extract added into broiler diets at different levels on serum protein fractions. A total of 112 Ross 308 broiler chicks were used in the study. Experiment consisted of control and 3 treatment groups with a 28 chicks within each group. Each experimental group was divided into four subgroups consisting of4 chicks. A basal (control) diet was prepared and three experimental diets were established by addition of P.major into basal diet; P.major 1 (5 g/kg feed), P.major 2 (10 g/kg feed), P.major 3 (15 g/kg feed). Broiler chicks were fed with these diets for 42 days ad libitum. Total protein levels of P.major 3 group were lower than other groups and controls. It was determined that the albumin percentages and levels became decreased in a significant ratio in the P.major 1 and P.major 2, (P<0,05), Alpha 1 globulin percentage and concentration were found significantly high in P.major 2 group than the other groups (P<0.05), Alpha 2 level and percentage in P.major 1 group was seen significantly higher than the control group, the A/G ratio in P.major 1 and P.major 2 was seen significantly lower than the control group. There was no significant difference between groups for beta and gamma globulins as percentage.