This study was conducted to study the effects of dietary L-arginine(L-Arg) level on amino acid digestibility, serum amino acid content and serum biochemical indices of growing minks. Seventy healthy female mink at the age of 60 days were randomly divided into 7 groups with 10 replicates per group and 1 mink per replicate. The mink in 7 groups were fed experimental diets with L-Arg supplementation levels of 0(group Ⅰ), 0.20%(group Ⅱ), 0.40%(group Ⅲ), 0.60%(group Ⅳ), 0.80%(group Ⅴ), 1.00%(group Ⅵ) and 1.20%(group Ⅶ), respectively. The pre-test period lasted for 7 days and the trial lasted for 60 days. The results showed as follows:1) the digestibility of serine, glutamic acid, proline, glycine, alanine, valine, isoleucine, tyrosine and lysine in group Ⅱ was significantly higher than that in groups Ⅲ, Ⅳ, Ⅴ, Ⅵ and Ⅶ(P<0.05 or P<0.01). The digestibility of aspartic acid, threonine, leucine and phenylalanine digestibility in groups Ⅱ was significantly higher than that in groups Ⅲ and Ⅳ(P<0.05 or P<0.01). 2) The serum arginine content in groups Ⅵ and Ⅶ was significantly higher than that in groups Ⅰ, Ⅱ and Ⅲ(P<0.05). There were no significantly differences in the other serum amino acid contents among all groups(P>0.05). 3) The serum total protein content in groups Ⅳ was greatly significantly higher than that in groups Ⅴ and Ⅶ(P<0.01), and was significantly higher than that in groups Ⅰ and Ⅵ(P<0.05). The serum albumin content in group Ⅲ and Ⅳ was greatly significantly higher than that in groups Ⅰ, Ⅴ, Ⅵ and Ⅶ(P<0.01). The serum globulin content in group Ⅳ was significantly higher than that in groups Ⅰ, Ⅴ and Ⅶ(P<0.05). The serum alkaline phosphatase activity in group Ⅳ was significantly higher than that in groups Ⅰ, Ⅱ, Ⅴ and Ⅶ(P<0.05). The serum lactic dehydrogenase activity in group Ⅳ was significantly higher than that in groups Ⅰ, Ⅱ, Ⅴ and Ⅶ(P<0.05). There were no significantly differences in serum alanine aminotransferase and aspartate aminotransferase activities among all groups(P>0.05). 4) The serum immunoglobulin M content in group Ⅲ was significantly higher than that in group Ⅰ(P<0.05). The serum complement 3 content in groups Ⅱ, Ⅲ and Ⅳ was significantly higher than that in groups Ⅰ, Ⅴ, Ⅵ and Ⅶ(P<0.05). There were no significantly differences in serum immunoglobulin A, immunoglobulin G and complement 4 contents among all groups(P>0.05). Through this trial study and regression analysis, when dietary L-Arg supplement level is 0.20% to 0.41%(dietary L-Arg total level is 1.65% to 1.86%), the growing minks can get better amino acid digestibility and serum biochemical indices.