Ecological and Taxonomic studied on the interstitial ciliates on the Red Sea Coast at Obhur, Kingdom of Saudi Arabia Saleh Al-Farraj Faculty of Education, King Saud University, KSA salfarraj@hotmail.com Abstracts Sediment samples were collected from four sites at both AlJanubiyah and Al-Shemaliyah on one occasion in early Spring and early Summer of the year 2007 in order to make a comparative study of ciliates abundance and diversity. The Temperature , Ph and Salinity were measured at the time of collection. Also water content and Organic matter of the sediments were determined. The ciliated protozoa were identified in sub-samples of sediments, to families and species level and enumerated. Ciliates belonging to 25 and 28 species were recorded in the sediments of Al-Janubyah and Al-Shmalyah, respectively. Keywords : Protozoa, Ciliates, Red Sea, Obhur, Ecological Factor.