To determine the Ostracoda fauna of the Istranca region, this preliminary study was performed and seven stream, Kuzuludere, Büyükdere (Çilinkozdere), Sultanbahçedere, Papuçdere, Elmalı, Kışla and Efendi stream, located in Istranca region, were investigated. In this way, ten spe-cies; Ilyocypris bradyi Sars, 1890; Pseudocandona albicans (Brady, 1864); Candona sp; Candonopsis kingsleii (Brady & Robertson, 1870); Physocypria kraepelini G. W. Müller, 1903; Heterocypris salina (Brady, 1868); Psychrodromus fontinalis (Wolf, 1920); Cypridopsis vidua (O.F. Müller, 1776); Potamocypris variegata (Brady & Nonman, 1889); Limnocythere inopinata (Baird, 1843) were identified. The highest species number was found in Sultanbahçe stream. Also Pseudocandona albicans is new record for Thrace region of Turkey.