The present invention aims to provide a carrier for drug delivery that selectively accumulates in the kidney in the body, and shows high biodegradability and drug releasability in the kidney. The present invention relates to a compound in which a carbonyl group of serine is linked directly or via a linker to terminal amino group of linear polylysine, compound carrier for delivery, and a medicament for the diagnosis, prophylaxis, or treatment of a renal disease, containing the carrier for drug delivery, and a drug bound to the carrier directly or via a linker or encapsulated therein.