It is a main object of the present invention to provide a drug delivery system in which drugs can be changed or which can be recharged with drugs, which continuously delivers drugs at effective concentrations to local lesional sites in a body and allows the use of drugs for which it has thus far been difficult to achieve effective local concentrations for a variety of reasons and drugs which have been difficult to use due to adverse effects on tissues that are not sites of action. The present invention provides a drug delivery system comprising an indwelling medical device on which a biocompatible material having target molecules on its surface has been coated, and target-recognizing nanocarriers (e.g., bio-nanocapsules, liposomes, liposome preparations, and nanoparticles) in which drugs are encapsulated and which have target-recognizing molecules capable of specifically binding to the target molecules.