Ovarian follicles are the most important steroids producing structures of the avian ovary. The ovary of a mature goose generally contains 7-9 large preovulatory follicles arranged in a follicular hierarchy, several postovulatory follicles, and numerous small follicles, which have not entered the follicular hierarchy. It has been reported that in avian preovulatory follicles biosynthesis of sex steroid changes during maturation (Gomez et al., 1998; Lee et al., 1998). The cell theory for steroid production suggested that granular layer of preovulatory follicles primarily produce progesterone that are required as substrate for the production of androgen and estradiol by theca layer (Huang et al., 1979). The recently multiple-cell theory of steroidogenic suggest that theca layer can also synthesize progesterone, androgen and estradiol independent of granulosa layer (Nitta et al., 1991).