The cunaxid predacious mite, Coleoscirus horidula (Tseng) was extracted from leaf litter under cotton field plants in Qalyubia Governorate associated with spider mites, nematodes, scale insects as well as other small arthropods. The biological aspects of the predatory mite, C. horidula was determined on two preys, the free living nematode Rhabditis scanica Allegen and the acarid mite Tyrophagus putrescentiae (Schrank) at four different temperature degrees (20, 25, 30, 35°C) and 65-70 ± 5% RH. The predator passed through three nymphal stages, also the predator developed faster when reared at 35°C than 20°C. Obtained data showed that the type of prey and temperature affected significantly on biology of male and female of C. horidula. As it prolonged C. horidula life cycle, generation, longevity and life span when fed on free living nematodes R. scanica at 20ºC, while it was significantly decreased when fed on motile stages of acarid mite T. putrescentiae at 35ºC, as the periods decreased. Fecundity was significantly higher when the female fed on free-living nematodes recording 98.83 eggs/ female at 25°C and decreased to record the lowest number of deposited eggs at 35°C as45.67 eggs/ female on the same prey.