Abstract: This experiment was conducted to investigate the effects of dietary supplementation with Aqueous Extract of Portulaca oleracea (AEP) on growth performance, serum, liver and mucus immunity, and inflammatory factor gene expression in immune organs of common carp (Cyprinus carpio). A total of 240 juvenile carp (32.00±0.50) g were randomly divided into four dietary groups with three replicates in each group and 20 carps in each replicate. The control group was fed with basal diet without AEP, and the experimental groups were fed with basal diet supplemented with 0.25%, 0.50% and 1.00% AEP for 8 weeks, respectively. Results demonstrated the following key findings: 1) Compared with the control group, the final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR), feed coefficient (FCR), and feeding rate (FR) were not significantly affected (P>0.05). However, the viscerosomatic index (VSI) was significantly decreased and the condition factor (CF) was significantly increased (P<0.05). 2) The AEP 0.25% group manifested distinct serum profile alterations, with acid phosphatase (ACP) activity significantly elevated (P<0.05) and myeloperoxidase (MPO) activity markedly reduced (P<0.05) compared to controls. Serum immunoglobulin (Ig) levels showed a significant increase in the 0.50% AEP treatment group (P<0.05). 3) Liver analysis revealed significant decreases in alanine aminotransferase (GPT) activity for both 0.25% and 1.00% AEP groups compared to controls (P<0.05). The content of Ig and the activity of alkaline phosphatase (AKP) in 1.00% AEP group were significantly increased (P<0.05). 4) Compared with the control group, AKP activity in the mucus of carp in the 0.50% AEP group was significantly increased (P<0.05), with no change in Peroxidase (POD) or protease activities (P＞0.05). 5) The mRNA expression analysis revealed that TNF-α and TGF-β levels in spleen tissue were downregulated in the 0.25% and 0.50% AEP groups (P<0.05), and TNF-α was also reduced in the 1.00% AEP group (P<0.05). In kidney tissue, IL-1β expression was significantly down-regulated across all AEP treatments, while IL-10 was significantly reduced in 0.50% and 1.00% AEP groups (P<0.05). In conclusion, dietary AEP supplementation enhance the immune function in serum, liver, and mucus of common carp without affecting growth performance. It also modulates the gene expression of inflammatory factors in immune organs, suggesting a potentially beneficial role in immune response process of the organism.