The experiment was performed to investigate the effects of Astragalus polysaccharide supplementation on the growth,immune function,and disease resistance of Macrobrachium rosenbergii.A total of 1 920 shrimp with the weight of(1.08±0.04)g were randomly assigned to six groups with four replicates per group and 80 shrimp per replicate.The control group(CON group)was fed a basal diet,while the experimental groups were fed a basal diet supplemented with 0.1%(0.1%APS group),0.2%(0.2%APS group),0.3%(0.3%APS group),0.4%(0.4%APS group),and 0.5%(0.5%APS group),respectively.The experiment lasted for 60 days.The results showed that compared with the CON group,0.3%APS group significantly increased the weight gain rate and specific growth rate of Macrobrachium rosenbergii(P<0.05),while the feed coefficient was significantly decreased in 0.3%APS group,0.4%APS group,and 0.5%APS group(P<0.05).Compared with the CON group,the serum lysozyme activity of Macrobrachium rosenbergii was significantly increased in 0.4%APS group and 0.5%APS group(P<0.05).The serum alkaline phosphatase,intestinal trypsin and lipase activities of Macrobrachium rosenbergii were significantly greater in 0.3%APS group,0.4%APS group,and 0.5%APS group compared to the CON group(P<0.05).After seven days of Aeromonas hydrophila challenge,the cumulative mortality of Macrobrachium rosenbergii in 0.3%APS group,0.4%APS group,and 0.5%APS group was significantly lower than that in CON group(P<0.05).The study indicates that the growth,immunity,digestive enzyme activity,and disease resistance of Macrobrachium rosenbergii were positively influenced by Astragalus polysaccharide,and the recommended supplemental level is 0.3%.