Effects of daily oral administration with ethanolic Moringa oleifera seeds extract (EMS), as an improving factor, were investigated on physiological and semen quality traits of NZW rabbit bucks. Adult bucks (n=40) were randomly divided into four groups of 10 bucks in each. Bucks were daily treated with oral dose of EMS (0, 900, 1200, and 1500 mg/buck) for 16 weeks; 8 weeks as a preliminary interval, and 8 weeks as a main semen collection interval. Results showed that all levels of EMS administrations mass motility, progressive motility, livability, membrane integrity of spermatozoa, sperm cell concentration, total sperm output, motility index, semen initial fructose, blood plasma FSH and LH, hemoglobin, red blood cells and globulin as well as testosterone, total proteins, albumin, and antioxidants capacity in blood plasma and the seminal plasma, epididymal weights, and spleen-somatic index were increased (P<0.05), while semen pH value, abnormality, acrosomal damage of spermatozoa, platelets, lipid profile, the activity of aspartate and alanine aminotransferase, and malondialdehyde were decreased (P<0.05). Administration of EMS (900 mg/buck) improved (P<0.05) only white blood cells. Pregnancy rate and litter size at birth (live) and weaning, and kit viability rate at birth were (P<0.05) improved. Practically, it could be suggested that oral supplementation of EMS (900, 1200, and 1500 mg/buck) is a suitable tool for improving semen quality, antioxidant status, and reproductive traits of rabbit bucks, particularly EMS at a level of 900 mg/buck.