A trial was carried out on thirty Ossimi ewes aged 3-4 years, belonging to the Animal Production Research Station at Sids, with live weight ranging between 45 to 50 kg. The animals were randomly divided into 3 groups, each of 10 ewes with almost equal mean live body weight. Animals were given maintenance and productive diets according to their average body weight (NRC 1988). Concentrate feed mixture composed of 22% cotton seeds, 20% molasses, 44% wheat bran, 10% yellow maize, 2.5% ground limestone and 1.5% common salt. Water was provided ad-libitum during the whole experimental period with clover hay and rice straw. The trial started 1^st June and ended 1^st August 2018 (2 mo. /wool growth) and included 3 groups; Control group; received the basal diet only without any supplements, the first group; was given the basal diet plus 0.23 gm selenoprotein / kg dry matter/ head/day (0.5mg available selenium), the second group; was given the basal diet plus 0.33 gm selenoprotein / kg DM /head /day (0.7mg available selenium). The trial included suckling period. The aim of this research was to study the effect of adding selenium to the diet of Ossimi ewes during suckling period on wool growth. Physical and mechanical wool properties were measured in addition to the estimation of Glutathione peroxidase (GPX) enzyme activity. Results showed that there was significant difference (P≤0.05) among groups in CWW, STL, FD, SST, ELO % and GPX enzyme activity, so, adding selenium was of a great importance at this period of lactating ewes on their wool production.