Before discovery of (pro)renin receptor, prorenin was regarded as a source of renin and probable diagnostic marker for diabetic nephropathy/Wilms' tumor. It is now considered that prorenin can perform renin activity by binding to (P)RR and binding mechanism of (pro)renin to (P)RR was indicated in many in vitro studies. Considering the physiological importance and pathological involvement of (P)RR, it is indeed a demand of time to determine the three dimensional structure of (P)RR to design (P)RR blocker(s) effective for (pro)renin. It may also facilitate to explain the incompatible data about the effective application of decoy peptide as (P)RR blocker. So far, studies have discussed the bindings of (pro)renin to (P)RR using peptides mimicking the structures of ligands (e.g., the decoy including "handle" region peptide, the "hinge" peptide etc). In this review, the binding mechanism of ligands has been highlighted from the structural aspect of (P)RR using several anti-(P)RR antibodies designed from the primary structure of (pro)renin receptor. Therefore, this review would give us a clue regarding the plausible binding region(s) for prorenin in the (P)RR.