Survey of mite species inhabiting leaves and debris of two varieties of citrus (navel orange and mandarin) in Fayoum governorate. The survey revealed the occurrence of 44 mite species, according to their feeding habits and systematic position. The population dynamic of some mite species inhabiting leaves of the two varieties of citrus (Eutetranychus orientalis Klein, Brevipalpus obovatus Dennadiu, Tydius californicus Banks, Pronomatus ubiquitus McGregor and their predators) for two years from May 2011 to April 2013 in Ebshway region, Fayoum governorate. The population dynamic of these mites was studied with the relation of biotic factors (predator mites) and a biotic factor (temperature and relative humidity) with this mite.