Fern is one of the vegetation that makes up the forest ecosystem in low, medium, and highland areas. This study aimed to analyze the diversity of ferns in Central Java at different heights. The research zone consists of zone I lowlands (Pagerwunung Nature Reserve, Darupono, Kendal, 100-300 masl), zone II medium plains (Forest Penggaron, 300 - 800 masl), and zone III highlands (Forest Mount Ungaran and Mount Lawu). The results showed that the diversity of plants in the zone I consisted of 8 families with 15 species, zone II consisted of 3 families with 23 species, and zone III consisted of 18 families with 32 species. The highest distribution of ferns diversity was in zone III because the increasing altitude causes the soil condition to become more humid. After all, forest trees provide water composition for the soil, lower temperatures make high air humidity, and light intensity is a suitable bioecological factor for all ferns’ habitat.