The paper reports results of ultrastructural studies (ТЕМ and SEM) оп the respiratory system in 9 species оf. mitеs belonging to the family Parasitidae. The respiratory system of mites includes pairs of stigmata, wperitremes, atria, as well as arising from atria tracheae and tracheoles. The role of peritremes and minute spines covering thеir аlls is discussed. ТЕМ studies have also revealed а specific morphology of tracheal wall in mites, dlffering from that hitherto described in insects.