Cinnamon is a plant with scientific name Cinnamomum zeylanicum that belong to Lauraceae family. This plant has many pharmaceutical effects which one of the best important uses is increasing of sexuality. In this research considered the effect of Cinnamon bark extract on male Balb/c mice reproductive system. At first, samples separated full casually, as six groups and in any of group eight samples, respectively as, experimental groups 1, 2, 3, 4 and two groups, control and placebo which kept in the same conditions. Cinnamon hydro-ethanolic extract provided in different dose (50,100,200 and 400mg/kg/2day) and injected intraperitoneally for 20 days to care groups and normal saline + ethanol were injected to placebo group (zero dose). These groups compared with control group. The hormonal experiments were measured by RIA technique.

The best important parameters in this research included: the testicles weight changes, probably histological changes in testis, change in number of sexual cells and density of LH, FSH and testosterone in blood of samples. The results indicated that cinnamon significantly can be increase the level of LH and FSH in dose of 200, 400 mg/kg. The density of testosterone increased in dose of 50, 100 mg/kg also the number of sperms and primary spermatocytes raise in 100, 200, 400 cinnamon extract but no significant differences were observed in weight of testicles and histological changes. The finding of this research indicated the positive effect of cinnamon extract on male reproductive system and hormone change in pituitary-gonad axis because sperm count and secretion of FSH hormone meaningful improve in dose of 200,400 mg/kg.