The altitudinal distribution of 31 genera and 62 species of fems and allied plants has been studied along three transects in the Carrizal, Chaina and San Pedro sections. The transects of the Carrizal and San Pedro sections rise to San Pedro de Iguaque lagoon trough westem and eastem slopes of the septentrional zone of Fauna and nora Sanctuary of Iguaque. The genera richest in species are polydium with 11 species, Asplenium, Elaphoglossum y Blechnum with 5 species. The typical genera of paramo are lamesonia, Lycopodium, Huperzia, Blechnum and Isoetes The distribution and number of species was compared in three sections: species number is highest in Carrizal section; in San Pedro section the number is low but there are sorne predominant species: Pleridium sguilinum (L.) Kuhn, lycopodium thyodies Willd. and Cheilanthes lendigera (Cav.) Sw. Of vegetation of Chaina section is a transition of montane low forests. of higher number in this section is probably due to location in the Iguaque or Cane bed river. Of taxa are concentrated between Andean forest and subparamo zones. Fem species seem limited in their distribution and are considered specific in their ecological requirementa.