Selenium is an essential trace element for wool growth and its characteristics especially during the exposure of animals to stress. Twenty  adult, dry, non-pregnant ewes aged 3-4 years old ranging from 45 to 50 kg body weight ,were chosen for the trial and divided into two equal groups, each of 10 ewes. The ewes were fed on a formed diet according to National Research Council (1985). The control group was fed on the formed diet without any supplements. The treated group was fed on the same diet plus 0.33gm selenoprotein  (0.7 available selenium)The trial lasted for one year. The grease Fleece Weight(GFW), Clean Fleece Weight(CFW), FibreDiametre(FD), Staple Length(STL), Fibre Length(FL), Staple Strength(SST), Elongation percentage(ELO%) and Glutathione Peroxidase enzyme(GPX) in the blood serum were measured to study the effect of long term supplementation of selenium on wool production and quality in sheep. GFW, CFW, STL and FL weren't affected significantly. The FD in tip portion was affected significantly P≤ 0.5 by the addition of selenoproten to the diet of the ewes. There was a significant difference between treated and untreated group in the sulphur content of the tip. The GPX was significantly higher in the treated group compared to control one. No significant difference between treated and untreated group in SST and elongation percentage.Addition of selenium to the diet of dry – non pregnant ewes didn't greatly affect wool production or quality in natural environmental conditions since there were no stresses on animals.