Structural polypeptides of feline parvovirus (FPV) subspecies viruses, that is, feline panleukopenia virus (FPLV), mink enteritis virus (MEV) and canine parvovirus (CPV), were comparatively investigated. Viruses propagated in the Crandell feline kidney (CRFK) cell culture were purified by equilibrium density gradient centrifugation in CsCl and were examined by electron-microscopy and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Virus infected CRFK cells were also analyzed by SDS-PAGE to determine virus-specific polypeptides. The purified virion of each subspecies contained three size classes of polypeptide which were almost identical for all three viruses: VP 1 (84, 000), VP 2 (64, 000) and VP 3 (63, 000). The characteristics of FPV polypeptides revealed in the present study were very similar to those of other members in genus Parvovirus and the results indicate that FPLV, MEV and CPV can not be distinguished by the SDS-PAGE analysis of purified virions.