L-Arginine has hypoglycemic and antioxidant effect in Alloxan diabetic animals and reduce effect of diabetes complication on spermatogenesis. antioxidant have essential effect on spermatogenesis, L-Arginine has antioxidant and hypoglycemic effect. Enhanced oxidative stress and changes in antioxidant capacity are considered to play an important role in the pathogenesis of chronic diabetes mellitus. Sixteen mature male rats aged 10 weeks, were randomly divided into four equal groups as follows 1st diabetic group (DG) that received 150 mg/kg (IP) Alloxan single dose; 2nd group diabetic group treated with (L-Arginine-Hcl)(DAG) received 150mg/kg (IP) Alloxan as single dose plus L-Arginine-Hcl 200mg/kg (IP)-per day, 3ed group treated with (L-Arginine-Hcl)(AG) received 200mg/kg-(IP) perday, and 4th were control group (CG) non treated. In 60 day the blood samples collected from heart to make serological parameters (glucose level) and testes removed to observe their Histopathological.