The pituitary adenohypophysis was obtained from thirty buffaloes-cows, their age's ranges from one month to12 years. Sections of adenohy-pophysis tissues were immuno-stained for α, βa, and βb subunits of inhibin hormone. Positive immuno-staining specific for the α subunits of inhibin were detected in the cells of the follicles of the adenohypophysis in all ages. Moreover, immunostain-ing specific for the inhibin βa subu-nits were strong positive at one month, weak positive at 4.5, 8 and 12 years and were negative at 8 months and 1.5 years. However, the immunostaining specific for the in-hibin βb subunits were positive at one and 8 months, 8 and 12 years and weak positive at 4.5 years and negative at 1.5 year. RT-PCR anal-ysis revealed that both α and βb subunits are expressed in all ages except at 1.5 years old animals while βa subunit is only expressed at young age.