The present invention provides a modified atrial natriuretic peptide that exhibits prolonged duration time in blood and maintains cGMP elevating activity. The present invention provides a modified peptide in which at least one sugar substance is linked directly through a glycosidic bond or via a linker structure to at least one hANP peptide, or a pharmaceutically acceptable salt thereof, a medicament comprising the modified peptide or the salt thereof as an active ingredient, etc.
