An 8-week growth experiment was conducted to investigate the dietary effects of different levels of antibacterial peptides extractives from musca domestica ，Litopenaeus vannamei with initial body weight）g. Each diet was fed to four replicates of 40 shrimps. The results showed that antibacterial peptides extractives of musca domestica could enhance survival ratespecific growth rate and feed efficiency ofP），weight gain ratewhich were significantly higher than those in control. By using the model based on WGRan optimum dietary antibacterial peptides extractives level of 2 900 mg/kg was calculated. The shrimps fed on the diets with antibacterial peptides extractives at 2 000-3 000 mg/kg had significantly higher body crude protein content and body ash contents. The body crude lipid content was not significantly affected by the supplemental levels of antibacterial peptides extractives. The number of haemocytes in shrimp fed on the diets with antibacterial peptides extractives at 2 000-5 000 mg/kg was significantly higher than that of control. The highest phagocytic rate was obtained in the shrimps fed on the diet with antibacterial peptides extractives at 3 000 mg/kg. When antibacterial peptides extractives were at 2 000-3 000 mg/kgLZM and T-AOC in serum. The activities of SOD in serum were not significantly different among all the groups）. There were no significant difference among all the groups in the activities of AKPSOD and T-AOC in hepatopancreas. The highest activities of LZM in hepatopancreas were obtained in shrimp fed on the diet with antibacterial peptides at 3 000 mg/kgsignificantly higher than the others. The results suggested that the dietary supplementation of pertain level of antibacterial peptides extractives could improve the growth performance and immune-related indicators in