The aim of this study was to evaluate the effects of xylooligosaccharide (XOS) on growth performance, hemato-immunological responses, body composition and digestive enzymes activity of sobaity seabream juvenile (Sparidentex hasta) with an average weight of 35.64 ± 0.30 g. Fish were fed with experimental diet containing 0, 5 and 10 g xylooligosaccharide kg-1 for 8 weeks. The obtained results indicated that dietary xylooligosaccharide did not change sobaity seabream growth, feed utilization and body composition (P > 0.05). The results of this study indicated that different levels of prebiotic did not affect hemato-immunological parameters except for complement activity (P< 0.05). Digestive enzymes including lipase and amylase activity did not affected by XOS-treatment but, protease activity decreased significantly in fish fed 0.5 % XOS compared to the control group (P< 0.05). Overall, results revealed that adding 0.5 % XOS could be beneficial as an immunostimulant for general health status as well as an immune and stress resistance promoter. There were no significant effects through dietary XOS on other parameters measured in the present study. Therefore, it is concluded that the levels of dietary XOS can differ according to the aim of use.