Interleukin（interleukin，IL）-33 can be expressed in various tissues and cells. It plays an important role in the maintenance of homeostasis and the response to environmental stress. It can participate in the formation and development of many diseases through IL-33/ST2 signaling pathway. Studies have shown that IL-33 is involved in maternal and fetal interface immune tolerance and placenta formation，while abnormal expression of IL-33 is related to the formation and development of pregnancy-related diseases such as abortion，preterm delivery and preeclampsia. The roles of IL-33 in pregnancy are deeply studied，and it may provide new ideas for the diagnosis and treatment of normal pregnancy maintenance and pregnancy specific diseases.