The article provides information about moisture demand and life forms of fern species, which spread in the flora of Nakhchivan Autonom Republic. It was noted that a class, 2 series, 6 families and 15 species including 11 genera of ferns spreading in the territory for humidity insistence, divided 4 ecological group (xerophyte, mesoxerophyte, mesophyte, mesohygrophyte), also it was identified that ferns divided 3 groups for their light demand (loving shade, resistant to shade and loving light). The article provides information about division 2 group of fronds of ferns for their existence durability (being green in summer and being green in winter) and life form divide 3 group for morphological structure of rhizomes (long rhizomatous, short rhizomatous and lawn maker).