In order to determine the catch composition of trawl in Chabahar region (Sistan and Baluchistan coastlines), the present study was carried out in Chabahar, Konarak and Pozm ports in June 2016. 23 species belonging to 15 families were caught and identified after seven times trawling. Mean while, the maximum composition catch (63%) was observed in Cutlass fish (Trichiurus lepturus). This is while, the minimum composition catch (0.05%) belonged to Areolate Grouper (Epinephelus areolatus), Gulf torpedo (Torpedo sinuspersici), Orange-spotted grouper (Epinephelus coioides), Gold bandedjob fish (Pristipomoides multidens) and Giant catfish (Netuma thalassina). The maximumlength-frequency of Cutlass fishwas observed in the length class of 77.5 – 88.5 cm. Based on the biodiversity and indices analysis regarding the caught fish, Simpson and Shannon indices were estimated as 0.692 and 2.459, respectively. In addition, natural richness was 29.9 and evenness was calculated as 0.185 using Camargo equation.