It has been observed that the avifauna has not been given proper attention with particular reference to the subspecies level. Thereby, an attempt has been extended to review the taxonomical status of the class Aves. The order Gaviiforms, family Gaviidae, genus Gavia which viz., only species Gavia stellata with subspecies G.s. stellata representing from Pakistan. However, in order Podicipediforms, family Podicipedidae includes two genera, which are Tachybaptus and Podiceps which represents five species T. ruficollis, P. cristatus, P. grisegena, P. auritus and P. nigricollis with five subspecies T.r.capensis, P.c.cristatus, P.g.grisegena, P.a.auritus and P.n.nigricollis. Secondly, order Procellariiforms, have two families Procellariidae and Hydrobatidae, where family Procellariidae contains two genera Puffinus and Bulweria. These two genera have four species P. tenuirostris, P. iherminieri and B. fallax with three subspecies P.t.tenuirostris, P.i.iherminieri, and B.f.fallax. Thirdly, family Hydrobatidae representing genus Oceanites has one species O. oceanicus with subspecies O.o.oceanicus from Pakistan. Whereas, order Pelecaniforms, contains five families Pelecanidae, Phalacrocoracidae, Anhingidae, Sulidae and Phaethontidae. Out of which, one family Pelecanidae, with genus Pelecanus, representing three species P. onocrotalus, P. philippensis, P. crispus along with three subspecies P.o.onocrotalus, P.p.philippensis, P.c.crispus from Pakistan. The study revealed that the above families represent thirteen species overall, with thirteen subspecies, where, three are vagrant, one migrant, one resident, one winter visitors, one summer vaster, one common, two recorded, two breeders and one Rare in Pakistan.