The aim of this study was to investigate the effect of different levels of Myrtle leaf powder on quantitative and qualitative parameters of sperm, antioxidant capacity of semen plasma, and blood superoxide dismutase activity (SOD) in Arabi ram in non-breeding season. 12 adult Arabic rams were used in 3 experimental treatments with 4 replicates per treatment. The treatments consisted of 3 levels of Myrtle leaf powder (0, 12.5 and 25 g/kg of DM). After 42 days feeding of experimental treatments, semen samples were collected and blood samples were obtained once a week for 4 consecutive weeks and the quantitative and qualitative parameters of sperm and total antioxidant capacity of semen were measured. Also, blood samples were subjected to measure testosterone level and SOD activity. 25 g/kg of myrtle powder had the best effect on improvement the sperm and semen characteristics include the motility (73.88%), viability (74.19%), morphological defects (10%), plasma membrane integrity (43.38%), semen volume (1.91 ml) and spermatozoa concentration (1.39 × 109/ml) as well as increased the seminal plasma total antioxidant capacity (TAC) (109.38 μmol/litr) and blood plasma SOD (500.19 U/ml) (p < 0.05). The blood sera testosterone concentration was not affected by treatments. A positive and significant correlation was found between the TAC and SOD with quantitative and qualitative parameters of sperm in Arabi ram (p < 0.05). In conclusion, the use of Myrtle leaf powder in diet improved reproductive performance, seminal plasma TAC and blood SOD activity in Arabi ram. The best result was obtained from 25 g/kg of this plant.