Abstract: Ultra-structure of the pituitary in Sinperca chuatsi was investigated during procreation. The pituitary gland consists of neurohypophysis and adcnophyphophysis. Two types of pituicytes and three types of neurosecretory fibers (A1, A2 and B) have been recognized in neurohypophysis. The neurosecretory terminals contain different diameter and shape of secretory granules. Neuraxon of type B neurosecretory terminals contain a lot of small clarity vesicles. Adcnophyphophysis is mainly composed of anteriorticrticotrophic cells, prolactin cells, growth hormone cells, thyrotrophs cells, gonadotrophic hormone cells, melanophore-stimulating hormone cells, periodic acid-Schiff-positive cells and one non-secretory cell type-stellate cells. The ultra-structural characteristics of pituitary in Sinperca chuatsi during procreating season are discussed.