Abstract: A 42-day feeding trial was conducted to investigate the effects of α-ketoglutarate (α-KG) on gill Na⁺/K⁺-ATPase activity and blood biochemical parameters of grass carp, Ctenopharyngodon idellus, exposure to ammonia. A total of 270 individuals initial body weight: (24.79±0.11) g were randomly assigned to 9 tanks, and these tanks were divided into three groups (Ⅰ: treated with 1.51 mg/L of aerated water and basal diet; Ⅱ: treated with 18.37 mg/L of ammonia solution and basal diet; Ⅲ: treated with 18.37 mg/L of ammonia solution and 0.75% α-KG added diet), with three replicates per each group (n=30). Experimental fish were sampled on 1st, 14th, 28th, and 42 days, respectively. The results showed that: (1) diet α-KG could effectively alleviate a significant increase in the content of plasma ammonia on the 1st day, the activity of plasma aspartate transaminase on 14th day and plasma alkaline phosphatase on 28th day, which were caused as being exposure to ammonia; diet α-KG could effectively alleviate a significant decrease in the activity of gill Na⁺/K⁺-ATPase on 28th day, plasma alanine aminotransferase on 28th and 42th days, and the content of plasma urea on 28th day because of being exposure to ammonia. Diet α-KG could significantly increase plasma globulin content on 28th day exposure to ammonia. In conclusion, dietary α-KG could alleviate the increase of plasma ammonia content exposure to ammonia, and maintain the stabilization in the activity of gill Na⁺/K⁺-ATPase, plasma alanine transaminase (ALT), plasma aspartate aminotransferase (AST), plasma alkaline phosphatase (ALP), and the content of GLB, as well as urea in grass carp exposure to ammonia.