To provide a glycosylated polypeptide having affinity to somatostatin receptors and, compared to somatostatins, having improved in-blood stability. The glycosylated polypeptide is characterized by at least two amino acids in a somatostatin or an analogue thereof being replaced by glycosylated amino acids.本發明提供一種附加糖鏈之聚胜肽,其對體抑素受體具有親和性,且與體抑素相比血中穩定性提高。本發明之附加糖鏈之聚胜肽之特徵在於:其係於體抑素或其類似物中,至少2個胺基酸經附加糖鏈之胺基酸置換。