In this study, reproductive characteristics of300 specimens(95 males and 205females)oforiental sole ( Brachirus orientalis ), one of the commercial species of Soleidae family in the Persian Gulf, with monthly sampling from August 2015 to July 2016, were studied.Sampling was performed inBushehr watersinnorthern Persian Gulfusing bottom shrimp trawls.Maleand femaleages werebetween 3 + to 11 + and 3 + to 17 + years, respectively. The sex ratio was 1M:2.2F. The mostfrequent age groups were 7 + and 11 + in males and females, respectively. The highest value of condition factor was observed in theAugust for male and was not significantly different from those of other months, except July. The highest value of condition factor was oerved inSeptember for females andwas not significantly different betweenOctober, January and April. The minimum, maximum and average absolute fecundity, were 22239, 174341 and 82212±46174 (SD= standard deviation), respectively. Thevalue of GSI in maleswas the highest in April and October (0.19) and these two months were notsignificantly different (P 0.05). Changes in liver index (HSI) in females during vitellogenesisin breeding seasons were high and its highest value was in February(1.01), but was not significantlydifferent from September (0.99) and April (0.95) (P 0.05).According to the gonadosomatic index (GSI), egg diameter, monthly distribution frequency ofdifferent stages of ovarian maturation, it was determined that the fish has two prolonged spawning seasons, one from July to November (with a peack in September, with an average GSI of 3.35and the other from February to May (with a peack in April with an average GSI of 4.48. The long spawning season indicated that this fish is a multiple spawner with asynchronous ovaries. Keywords : Sole, Brachirus orientalis , Soleidae, Persian Gulf, Reproduction Characteristics