Abstract: Testicular histological development in Japanese quail of different ages was stud -ied. Six stages in spermatogenesis were distinguished on the basis of microscopic examination. Primary spermatocytes were found in quails ages 11 days. Spermatids occured on day 36. The first mature spermatozoa were present in the seminiferous tubule on day 46. Some difference in structure and stainiing characteristic existed between the spermatids of the quail and those of other farm animal or chicken. The Leydig cells occured in quails before dayopersisted throughout spermatogenesis. This result was at variance with the changes seen in the Leydig cells of the domestic fowl. After 21 days of life, we could find a number of degenerative cells and some eosinophil bodies which consisted of several eosinocytes. Two, Three or even more nuclei were observed in the eosinophil bodies.