Study of longline's was carried out to identify the catch composition on the Persian Gulf water. The study areas were from Arvand-Rod to Musa- Khor. Sampling was carried out in three season’s spring, summer and autumn (9 mounths) on a cruise through out month.Twelve specie were caught and indentified. catch composition consisted of Acanthopagrus latus (Houttuyn, 1782), Acanthopugrus bifasciatus (Forsskål, 1775), Lethrinus nebulosus (Forsskål, 1775), Rachycentron canadum (Linnaeus, 1766), Epinephelus coioides (Hamilton, 1822), Pomadasys kaakan (Cuvier, 1830), Diagramma pictum (Thunberg 1792), Acanthopagrus cuvieri (Day 1875), Arius thalassinus (Rüppell, 1837), Carcharhinus sorrah (Müller & Henle, 1839), Rhynchobatusdjiddensis (Forsskål, 1775), Pastinachussephen (Forsskål, 1775). The grouper (Epinephelus coioides) and cobia (Rachycentron Canadum) were respectively accounted for the highest (24.19) and smallest (1.47) percentage of the fishing. Thisstudy reveals that thesize of fish and the depth have a positive relation ship.