Cinnamon has many therapeutic effects, such as its impact the increase of sexual ability. This experiment was conducted to determine the effect of cinnamon extract on spermatogenesis and hormonal axis of pituitary gonad in mice. The animals used in this study are male adult mice (weighing about 30-34 g and 9-10 weeks old). Cinnamon was purchased from one of the most valid shops in Jahrom and then powdered. After preparation of cinnamon extract, it was used for injection. The concentration of cinnamon used in this research was 10 and 20 mg/kg BW. The control animals received only drinking water. The sham group received distilled water. The treatment animals received cinnamon extract (10 and 20 mg/kg BW) for two weeks, each day for the amount of 1 mL interaperitoneally. After the injection, the animals were sacrificed. The weights of testes were measursed, and the changes, including the number of Sertoli cells, spermatogonia, spermatid, and Leydig cells were calculated. Also, hormonal concentration changes (LH, FSH and Testosterone) were measured by special hormonal kits. The results revealed significant increase (P<0.05) in the number of spermatogonia, spermatocyte, spermatid, Sertoli and Leydig cells in treated animals. Also, the results showed significant increase (P<0.05) in the concentration of LH, FSH and Testosterone hormones among treated animals. Due to the increase in LH, FSH and Testosterone hormones and also the increase of the number of Leydig cells, it is concluded that cinnamon may cause an increase in sex cells within seminiferous tubules in mice. پرونده مقاله