Abstract: Expressions of galectin-1 （Gal-1） in deciduas, placenta and trophoblast cells show a temporal and spatial pattern during pregnancy, which differ between normal and abnormal pregnancy. The expression level of Gal-1 gene is regulated by DNA methylation in its promoter region, and regulated by steroid hormones. Gal-1 takes parts in cell-adhesion, trophoblast differentiation, invasion, formation of syncytium and spiral artery remodeling. Gal-1 is also involved in the immune tolerance by promoting the immune inhibition transformed from the tolerogenic dendritic cells （ＤＣｓ）, cytokines and immunoprotrins. Meanwhile, the oxidative stress of placenta and maternal may change Gal-1 structure, and its biological activity and function. Gal-1 is a potential diagnosis marker or treatment target for the pathological pregnancy and pregnancy-related diseases, since it plays an important role in the initiation, development and maintenance of pregnancy.

Key words: Galectin 1, Placenta, Immune tolerance, Oxidative stress