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.