Abstract: Randomly selected healthy Xingguo grey geese with a male to female ratio of 1to 5were divided into two groups.The treatment group was exposed to artificial light, and the control under natural conditions.The pituitary, hypothalamus, ovary and oviduct were collected from the geese for tests.The mRNA expression of the PRL genes was found to decrease in all four organs, with the highest expression in the pituitary and the lowest in the ovary of the geese.The treatment group had a significantly lower expression in the pituitary and oviduct than control (P<0.05) , but did not differ significantly in the hypothalamus and ovary.