Biliverdin reducatase was purified from pig-kidney to homogeneous form through DEAE 52-cellulose, Sephadex G-100 and Procion red HE 3B-Sepharose 4B column chromatography, The enzyme was estimated to be a monomer with a molecular weight of 66kD by SDS-PAGE. A gel staining in basic-pyridine solution of heme was used to identify purified biliverdin reductase. The enzyme utilized NADPH and NADH as electron donors for the reduction of biliverdin to produce bilirubin. The apparent K(m) values for biliverdin were established to be 1.25 &mgr;M with NADPH and 2.52 &mgr;M with NADH.