The present invention discloses a method of producing polypeptides, including insulinotropic GLP-1 (7-36) polypeptide and/or GLP-1 analogs, by ligating genes in a tandem way. Also disclosed are the recombinant polypeptides produced by such a method. Using the method of this invention, 1 to 32 copies of GLP-1 (7-36) and/or GLP-1 analog genes may be expressed in tandem and the desired polypeptide can be obtained after cleavage of a fusion protein and further processes of separation and purification thus making possible the production of recombinant polypeptides, including recombinant GLP-1 (7-36) and/or GLP-1 analogs on a large scale, at a significantly reduced production cost.