The present invention provides a glycosylation atrial natriuretic peptide with extended sustaining properties in blood, and that has cGMP increasing activity. The present invention provides a modified peptide coupled to at least one saccharide directly by a glycoside bond, or coupled to at least one hANP peptide through a linker structure, and also provides a pharmaceutically permissible salt thereof, and a drug or the like containing the modified peptide or salt thereof as an active ingredient.