The present invention provides expression vectors and helper display vectors which can be used in various combinations as vector sets for display of polypeptides on the outer surface of eukaryotic host cells. The expression vector of the invention can be used alone for soluble expression without having to change or reengineer the display vectors. The display systems of the invention are particularly useful for displaying a genetically diverse repertoire or library of polypeptides on the surface of yeast cells, and mammalian cells.