We evaluated the apparent retention, the hepatic, tissue and plasmatic deposition as well as the efficiency of the enzyme hepatic and plasmatic Glutathione Peroxidase in broiler chickens fed different sources and levels of selenium. 300 male Cobb- 500 chicks aged 14 days were submitted to a factorial scheme 3x3+1 (three levels - 0.150; 0.300; 0.450ppm, three commercial sources - one inorganic and two organic + one control treatment without a supplementation) in CRD. The first 14 days of age (depletion period) the birds were fed basal diets without a supplementation of selenium. At 14 days the birds were given the diets with selenium for a period for 14 days, and the excreta collected in the last four days. The work suggested that the selenium retentions were relatively high, due to the use of organic source A at growing levels they presented a lower decrease in apparent retention of selenium. The organic sources participated more actively in the activities of tissues in general and the inorganic source is neutralized in the hepatic tissue. The efficiency of this enzyme in plasma was increased linearly, when we increased dietary levels for the inorganic source there was no change in efficiency.