In this study, the effect of ethanolic Aloe vera extract as a natural antibiotic on growth performance of common carp (Cyprinus carpio) was studied. Fish with an average weight of 29.74±1.20 g and the mean length of 11.50±0.28 cm were divided randomly into 4 treatments (a control and other groups treated with the extract of 0.1, 0.5 and 2.5% in the diet with 3 replicates and density of 10 fish per each replicate. After 8 weeks of feeding, growth parameters such as WG, SGR, FCR and FCE were examined. Comparing the results of the final length and weight and growth indicators in treatments fed with the extract were better in higher dose of extract. The results of this study showed that Aloe vera extract as a growth promoter, appetite stimulator, tonic and immunostimulant in the diet can reduce stress, reduce food losses and protect fish in order to better growth of fish.