Objective: The aim of this study for focused the light on the development structure of the testis of gazelle. Materials and Method: 10 healthy male gazelle were used to study the histology structure of testis (5 pre- Puberty and 5 post- Puberty). Results: The testis is surrounded by a thick, irregular connective tissue capsule. Each lobule of the testis is composed of seminiferous tubules and interstitial tissue, and trabecular and interlobular septa divide the lobules apart. Neighboring the seminiferous tubules are Sertoli cells and spermatogenic cells. From spermatogenic cells, spermatozoa are produced. The first spermatogonia are small, spherical cells with black, spherical nuclei that reside on the basement membrane. Spermatogonia were earliest stages of the spermatogenic cells. Larger cells with frequently distinct chromatin are called primary spermatocytes. Secondary spermatocytes are rare because of their quick second meiotic division and the haploid spermatids that follow. Spermatids are round, pale-nucleated cells that are grouped close to the lumen of the seminiferous tubule. Prostatogenic cells outnumber Sertoli cells in the body. Oval or triangular in shape, the nucleus has a light coloration. In the connective tissue separating adjacent tubules, Leydig cells are present. Lines the epididymis are pseudostratified epithelium. Extensions of the cytoplasm into the lumen are called stereocilia. In different proportions, there is circular smooth muscle, and a connective tissue lamina propria supports the epithelium. The rete testis is connected to the ductus epididymidis by the efferent ductules, which are convolutions of tubules. Numerous valved veins were visible in the tunica albuginea, which covered the initial ascending portion of the epididymal head. Cuboidal epithelium was lining extratesticular rete testis. Three different cell types; migrating, basal, and columnar had epithelial membranes lining the efferent ductules. Many columnar, non-ciliated cells with many cytoplasmic vacuoles and tiny granules lined the epithelium of the first segment of the efferent ductules. Conclusion: In post-puberty age, the structure of the gazelle's testis exhibited a pattern resembling that of other ruminants; the seminiferous tubules contain adult sperm and a broad lumen.