This study aimed to evaluate the effect of addition of aqueous or methanolic Moringa oleifera leaves extract (MOLE) at different levels (0, 100, 200 and 300 μg/ml) as antibiotic alternative to Friesian bull semen extender on sperm characteristics post-dilution, equilibration and thawed. The enzyme activity and antioxidant capacity of bull seminal plasma were determined in post-thawed semen. Five Friesian bulls (3-4 years old and 400-450 kg LBW) were used. Semen was collected from bulls by an artificial vagina twice a week for 5 weeks. After ejaculation semen was evaluated for mass motility and only the ejaculates of ≥70% percentage were pooled and diluted at 37⁰C using citrate-egg yolk extender and divided into seven portions, control (E1), 100 (E2), 200 (E3), 300 (E4) μg aqueous MOLE /ml semen extender or 100 (E5), 200 (E6), 300 (E7) μg methanolic MOLE /ml semen extender. After semen dilution it was equilibrated at 5⁰C for 4 h then it placed in liquid nitrogen at -196⁰C. Frozen semen stored for two month was thawed at 37⁰C for 30 sec. Semen samples were evaluated for characteristics including sperm motility, livability, abnormality, acrosome damage and hypo osmotic swelling test (sperm cells with curled tail) in diluted, equilibrated and thawed semen. Activity of AST, ALT, LDH, catalase and glutathione in post thawed samples seminal plasma were determined. The present results indicated that adding 300 μg of methanolic Moringa oleifera leaves extract to each 1 ml of citrate-egg yolk extender as an alternative to penicillin and streptomycin can improve quality of Friesian bull semen during different preservation stages.