The present invention relates to an oligosaccharide chain added GLP-1 peptide that has higher stability in blood than that of GLP-1 and, preferably, exhibits higher activity of controlling blood-sugar levels than that of GLP-1. The present invention relates to an oligosaccharide chain added GLP-1 peptide having GLP-1 activity, wherein at least one amino acid is substituted with an oligosaccharide chain added amino acid, in:(a) GLP-1； (b) a peptide having the amino acid sequence of GLP-1 with deletion, substitution or addition of one or several amino acids； or (c) a GLP-1 analog.本發明附加糖鏈胰高血糖素樣肽－1(GLP－1)胜肽，係有關於與GLP－1相比，血中半衰期長，且顯現高血糖值抑制活性之附加糖鏈GLP－1胜肽。本發明在(a)GLP－1(b)GLP－1中被缺失置換或附加1個或數個之胺基酸之胜肽；或(c)GLP－1之同系物中其特徵為至少1個胺基酸被附加糖鏈胺基酸置換來形成具有GLP－1活性之附加糖鏈GLP－1胜肽。
