Abstract: To research the morphology of alpaca pituitary and provide morphological basis for the endocrine function of alpaca pituitary. In this study, 7-month-old male alpaca pituitary was observed by the light microscope and transmission electron microscope. The results showed that alpaca pituitary located in pituitary fossa of the skull sphenoid were similar to the buffalo pituitary. It was ellipse, dorsal calm, gastro convex, and was composed of adenohypophysis(pars distalis, pars tuberalis, pars intermedia)and neurohypophysis, and existed pituitary cleft and undeveloped pituitary coelom. Pars distalis was 40%-45% of sagittal aera, and pars intermediate and pars nervosa rather developed, the ratio of oxyphil cell, basophilic cell and chromophobe cell was 8∶1∶11 in the pars distalis of alpaca pituitary. Somatotroph, thyrotroph, corticotroph, gonadotroph and follicular cell of the pars distalis of alpaca pituitary were found by transmission electron microscope, and somatotrophs was most. The results showed that pituitary structure of the 7-month-old alpaca was similar to that of most mammals, but had its unique characteristics.