Two trials were conducted to investigate the effects of adding Baclicus lincheniformi to diet or aquaculture water on growth performance and immunity of Litopenaeus vannamei. The average initial body weight of Litopenaeus vannamei in the two trials was about 1.06 g. In trial 1, shrimps in five groups were fed five experimental diets with different levels of Baclicus lincheniformi or probiotics A (D1 group, as blank control group: not adding probiotics; D2 group: adding 0.3 mg/kg Baclicus lincheniformi; D3 group: adding 3.0 mg/kg Baclicus lincheniformi; D4 group: adding 30.0 mg/kg Baclicus lincheniformi; D5 group, as positive control group: adding 80.0 mg/kg probiotics A, probiotics A was market complex-probiotics-preparation). In trial 2, shrimps in four groups were all fed the diet of D1 group in trial 1. Before the trial started, added 0 (d1 group, that was D1 group), 0.4 (d2 group), 4.0 mg Baclicus lincheniformi (d3 group) and 40.0 mg probiotics B (probiotics B was market complex-probiotics-water purifying agent; d4 group, as positive control group) to the aquaculture water in concrete tank (1 m×1 m×1 m, and effective water depth was 0.7 m), and then added 0, 0.2, 2.0 mg Baclicus lincheniformi and 20.0 mg probiotics B to the aquaculture water every 7 days, respectively. Each group had six concrete tanks and each concrete tank had eighty shrimps. The feeding time of trials 1 and 2 were all 8 weeks. The results of trial 1 were showed as follows: the final average body weight (FBW) of shrimps from D1 to D4 groups was significantly higher than that from D5 group (P<0.05), and no significant differences were found among D1 to D4 groups (P>0.05). The specific growth ratio (SGR) and weight gain rate (WGR) of shrimps from D2 group were significantly higher than those from D5 group (P<0.05), but without significant differences compared with D1, D3 and D4 groups (P>0.05). The feed conversion ratio (FCR) of shrimps from D2, D3 and D4 groups was significantly lower than that from D1 group (P<0.05), but without significant difference compared with D5 group (P>0.05). The survival rate (SR) of shrimps from D4 group was significantly higher than that from other groups (P<0.05). The hepatopancreas superoxide dismutase (SOD) activity of shrimps from D2 and D5 groups was higher, and significantly higher than that from other groups (P<0.05). The hepatopancreas total antioxidant capacity (T-AOC) of shrimps from D4 group was the highest, and significantly higher than that from other groups (P<0.05). The hepatopancreas malondialdehyde (MDA) content was decreased with the dietary Baclicus lincheniformi supplemental amount increasing, the hepatopancreas MDA content from D4 group was the lowest, and significantly lower than that from D1, D2 and D3 groups (P<0.05), but without significant difference compared with D5 group (P>0.05). The results of trial 2 showed as follows: adding Baclicus lincheniformi to aquaculture water had no significant effects on FBW, WGR, SGR and FCR (P<0.05). The hepatopancreas alkaline phosphatase (AKP), SOD activities and T-AOC of shrimps from d2 group were the highest, and significantly higher than those from other groups (P<0.05). The hepatopancreas lysozyme (LZM) activity of shrimps from d2 group was the highest, and significantly higher than that of shrimps from other groups (P<0.05). The hepatopancreas MDA content of shrimps from d1 group was the highest, and significantly higher than that of shrimps from other groups (P<0.05). In conclusion, the Baclicus lincheniformi can improve the immunity of Litopenaeus vannamei by means of adding Baclicus lincheniformi to diet or aquaculture water; the Baclicus lincheniformi adding to diet or aquaculture water has better effect than probiotics A or probiotics B with considering the growth performance and immunity of Litopenaeus vannamei; moreover, the supplemental amount of Baclicus lincheniformi in the diet of Litopenaeus vannamei should be controlled to 0.3 to 3.0 mg/kg base on consider the results of trials 1 and 2.