Constituting a stress model by repeatedly challenged with lipopolysaccharide (LPS) in weaned pigs, the experiment that was researched on effects of α-ketoglutaric acid (AKG) on growth performance and plasma hormones level was aimed at whether AKG could alleviate the reaction to stress in weaned pigs. Twentyfour healthy crossbred Duroc× Landrace×Largewhite weaned piglets with body weight of (7.25±0.23) kg were randomly allocated to 3 groups (control group, LPS control group and AKG group). Every group included 8 replicates and 1 piglet in per replicate. The control group and LPS control group were fed the basal ration adding with 1% amylum, while AKG group was fed the basal ration adding with 1% AKG. Piglets in LPS control and AKG group were injected intraperitoneally with 80 μg/kg LPS every other day (on day 10, 12, 14 and 16 of experiment). The results showed that: 1) from day 1 to day 9 (without LPS challenge), ADG in AKG group increased by 30.0% (P<0.05) and 31.1% (P<0.05) compared with control group and LPS control group, respectively; meanwhile, F/G decreased by 12.4% (P<0.05) and 12.8% (P<0.05); from day 10 to day 16 (with LPS challenge), ADG and F/G in LPS control group decreased by 28.8% (P<0.05) and increased by 16.8% (P<0.05) compared with control group, respectively; while, there was no significant difference between AKG group and control group on ADG and F/G (P>0.05); 2) in comparison with control group, insulinlike growth factor-Ⅰ (IGF-Ⅰ) of plasma in LPS control group decreased by 22.7% (P<0.05) after LPS challenged firstly (on day 10 of experiment), but no significant difference was found in AKG group and control group; after repeated challenge with LPS (on day 16 of experiment), IGF-Ⅰ and insulin of plasma in LPS group decreased by 21.2% (P<0.05)and 25.7% (P<0.05); meanwhile, these indexes had no significant difference between AKG group and control group (P>0.05). The results indicated that dietary supplementation with 1% AKG could significantly relieve the growth depression of weaned piglets challenged by LPS.