This study was to investigate the influence of housing system on lamb semen characteristics. Forty- eight Farafra ram lambs with an average weight of 19 kg and 4-5 months of age were used during summer. Ram lambs were randomly divided into six groups and housed under six housing systems, they are differed mainly in the type and highest of roofs, as follow: 1) Semi open type house shaded with asbestos sheets (AS); 2) Semi open type house shaded with straw earth floors (S); 3) a close type shaded with single asbestos roof at 3 m height (single low type, SL); 4) a close type shaded with single asbestos roof at 5 m height (single high type, SH); 5) a close type shaded with double asbestos roofs at 3 and 3.5 m height for two roofs, respectively (double low type, DL); 6) a close type shaded with double asbestos roofs at 5 and 5.5 m height for two roofs, respectively (double high type, DH).. The experiment period lasted for 5-6 months. Semen was collected and evaluated for determination of volume, mass movement, pH, sperm concentration, live and dead sperm, abnormal spermatozoa and semen index. All results were analyzed using GLM procedure of SAS. Ram lambs in closed houses had higher sperm concentration per ejaculate, sperm concentration per ml, sperm motility and live sperm concentration than those in semi open one. Also, Ram lambs in closed houses had lower abnormal spermatozoa than those in semi open one