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The study aims to determine the effects of graded farming on growth performance and non-specific immunity factors of shrimp Litopenaeus vannamei Boone. Three size groups of shrimp,i.e:,the small size group [Gs,with an average body length (BL) of (3.04±0.36) cm and body weight (BW) (0.412±0.35) g],the large group [GL,with a BL of (4.29±0.55) cm and BW of (1.098±0.42) g],and the ungraded group [Gm,with a BL of (3.47±0.81) cm and BW of (0.611±0.79) g],were reared under the same conditions for 8 wk. Growth performance and non-specific immunity factors were measured. The results showed that BW gain,biomass gain and the specific growth rate of body length (SGRL) were significantly influenced by size grading (one-way ANOVA,P0.05) was found on phenoloxidase (PO) activity among the three size groups. Synthetically,size grading could enhance growth and rearing efficiency,and did not have a significant influence on the immunity of L. vannamei Boone.Therefore,graded farming in L. vannamei Boone was feasible in the culture practice.