This experiment was designed to investigate the effects of dietary different concentrations of mulberry leaf polysaccharide （MLWE） on the growth performance, hepatopancreas immune indicators, antioxidant capacity, and intestinal health of Macrobrachium rosenbergii juveniles. The basal diet without mulberry leaf extract was used as the control group （MLWE0）, and on this basis, 3 g/kg （MLWE3 group）, 6 g/kg （MLWE6 group）, 9 g/kg （MLWE9 group） and 12 g/kg （MLWE12 group） of mulberry leaf extract were added to the basal diet to prepare five groups of isonitrogenous and isolithiatic diets, respectively. The healthy and active larvae of M. rosenbergii juveniles with initial body weight of （0.75±0.09）g were selected as the research objects. Each experimental group was set up with 3 replicates, and the experimental period was 56 days. The results indicated that： In comparison with the control group, the final average weight, specific growth rate and weight gain rate of the MLWE6, MLWE9, and MLWE12 groups increased significantly （P<0.05）, on the contrary, there was lower feed conversion ratio in MLWE6, MLWE9, and MLWE12 groups than that of the control group （P<0.05）. With the increase of MLWE supplemental level in dietary, the thickness of intestinal muscle layer decreased in groups of MLWE3, MLWE6, and MLWE9, while there was an increase in height and width of intestinal folds compared with the control group. Although there were no notable changes in intestinal microvilli height between the control group and treatment groups, high density of intestinal microvilli was observed on experimental group. Significantly lower levels （P<0.05） for malondialdehyde （MDA）, superoxide dismutase （SOD）, catalase （CAT）, and glutathione peroxidase （GSH-Px） were observed on the experimental groups compared to the control group, in addition, compared to the control group, there were higher expression levels of immune-related gene in hepatopancreas of prawn fed diets with 6 and 9 g/kg mulberry leaf water extract （P<0.05）, the relative abundance of pathogenic bacteria （such as Aeromonas hydrophila and Vibrio cholera） in the intestinal microbiota of M. rosenbergii juveniles was significantly reduced in the MLWE6, MLWE9, and MLWE12 groups （P<0.05）. In conclusion, adding appropriate concentrations of MLWE to the basic diet of M. rosenbergii juveniles can promote their growth, enhance their non-specific immunity, and improve gut health. Based on the comprehensive analysis and the index of weight gain rate, it is suggested that the appropriate addition level for mulberry leaf water extract in the diet of M. rosenbergii juveniles is between 6 and 9 g/kg.