Abstract: Investigated the relationships between the pinealocyte and the seasonal breeding, in order to provide reference for revealing the endocrine mechanism of goat’s seasonal breeding. Seasonal changes of Jining gray goat’s pinealocyte was observed by TEM. Results:①The pinealocyte can be classified into light cell and dark cell, and the smooth endoplasmic reticulum(SER) is more abundant than the rough endoplasmic reticulum(RER) in light cells,while the RER are abundant in dark cells. Another thing is that the Golgi complex and mitochondria are more complex in light cell than which in dark cell, but in dark cells there are more glycogen.②In summer pinealocyte there are mainly dark cells, and light cells is less, but in spring the light and dark cells are more. The seasonal changes of functional activity in Jining gray goat’s pinealocyte was showed.

Key words: Jining gray goat; pinealocyte; ultrastructure; seasonal changes