In this study, the effect of artemisia (Artemisia annua) leaves extract (ALE) on the immune system, growth performance and antioxidant capacity of common carp (Cyprinus carpio) was investigated. Fish with initial weight (90.32 ± 1.12 g) were fed various levels of ALE (0, 0.5, 1 and 1.5 g/kg) for 8 weeks. The results showed that the growth performance (FW, WG, SGR, PER, and LER) in fish fed 1 g/kg ALE was increased significantly (P<0.05) and the feed conversion ratio (FCR) was improved in fish fed 1 and 1.5 g/kg ALE in comparison to the control group (P<0.05). Skin mucus total protein was higher in fish fed diet containing 0.5 g/kg ALE than the other experimental groups (P<0.05), while the lysozyme, immunoglobulin and protease was increased by increasing of ALE in diets. Respiratory burst activity and serum immune parameters were higher in fish fed 0.5 g/kg ALE than the other treatments (P<0.05). Increasing of catalase (CAT) and decreasing of malondialdehyde (MDA) were observed in fish fed ALE, while glutathione peroxidase (GPx) increased only in fish fed 0.5 g/kg ALE. Hence, it can be concluded that ALE has considerable potential as a natural immunostimulant and growth promotor supplement for the common carp’s aquaculture.