This study was conducted to evaluate the effects of different levels of garlic powder on growth factors, survival rate and body composition of cultured Litopenaeus vannamei by Caspian Sea water. Four groups of beluga sturgeon with mean weight of 34.20± 0.44 g were raised for 56 days in fiber glass tanks (20 shrimp to each tank) and feeding with different levels of garlic powder with concentrations of 0%, 0.25%, 0.5% and 1.0% (Three replicates were used for each concentration). At the end of the trial, growth factors (Mean weight increased, percent of weight increased, feed conversion ratio and specific growth rate) and body composition were determined and compared with control group. Our results confirmed that shrimp fed on diet supplemented with 1.0 % garlic powder had significantly higher growth factors and survival rate compared to other treatments (P<0.05). The study of body chemical composition showed significant difference in percent of protein was observed in 1.0% treatment compare to 0.25% and control groups (P<0.05), although, no significant difference in moisture, crude lipids and Ash percentage was observed between different treatments (P>0.05). Based on the results, using of garlic powder, especially at the level of 1.0% in order to improve the growth performance, survival rate and body composition of L. vannamei is recommended.