Implantation is the attachment of embryo in the endometrium. Failure in implantation is a major cause of early pregnancy loss. During implantation, the temporal uterine lumen closure can help embryo attach to the uterus. In pigs, extending of endometrial folds to form interlocking finger-like projections is a main cause leads to uterine lumen closure during attachment time, but the underlying mechanisms are largely unknown. Our data reveal that pig uterine luminal epithelium (LE) migrate in coordinated groups during extending of endometrial folds. Moreover, the MALDI-TOF MS based N-glycomic characterization of porcine endometrium revealed α2,6-linked sialic acid are highly expressed in pig uterine LE during extending of endometrial folds. To investigated the mechanisms by which α2,6-sialylated proteins in formation of the endometrial folding during implantation in pigs, the α2,6-sialylated proteins in pig uterine LE were characterized by proteomic analysis and those proteins that are involved in cell adhesion, such as E-cadherin, were detected. Finally, our in vivo and in vitro data show that α2,6-sialylation of E-cadherin occurs in accompany with collective epithelial migration. The results provide new insight into the mechanism of pig implantation by identifying that α2,6-sialylation of cell adhesion molecules may participate in formation of extending of endometrial folds through promoting of collective migration of uterine LE.