The present invention aims to provide a polypeptide having a partial sequence of lacritin, which is capable of promoting adhesion between a cell and an extracellular matrix； and a polypeptide having a partial sequence of lacritin, which has an action to promote tear fluid secretion. The present invention provides a polypeptide comprising the amino acid sequence of SEQ ID NO: 1, which is a particular partial sequence of lacritin, and having an amino acid length of not more than 70 residues. The polypeptide of the present invention can promote adhesion between a cell and an extracellular matrix. The polypeptide of the present invention can promote tear fluid secretion from lacrimal gland acinar cells.
