Abstract: Stem cells are a class of cells with self-renewal and multi-lineage differentiation potential. According to their derivation, stem cells can be classified as embryonic stem cells (ESCs), adult stem cells (ASCs) and induced pluripotent stem cells (iPSCs). The germ cell lineage is responsible for transmitting genetic and epigenetic information across generations, and for ensuring new individuals. Human assisted reproductive technology (ART) could solve some intractable infertility problems, but it cannot help such infertile women as premature ovarian failure (POF) due to germ cell deficiency. If germ cells could be in vitro induced and differentiated from stem cells, it would be possible to help those POF patients to achieve their healthy offsprings through ART. Gametogenesis are involved in several complicated and rigorous steps, including primordial germ cell (PGC) specification, proliferation, migration to the gonadal ridges and final differentiation into mature gametes such as oocytes. However，the detail of gametogenesis has not been clearly elucidated up to now. Recently, many  in vitro models were developed to differentiate female germ cells from stem cells，with some encouraging achievements.

Key words: Germ cells, Embryonic stem cells, Multipotent stem cells, Induced pluripotent stem cells, Adult stem cells, Cell differentiation