【Objective】 To provide scientific evidence for clinic to treating the children with simple obesity by studying the distributions of 17 amino acids in the serum and researching the relation between the levels of amino acids and simple obesity. 【Methods】 The levels of 17 amino acids of 78 patients and 40 healthy children were detected by high performance liquid chromatography(HPLC). 17 amino acids included Thr, Val, Ile, Leu, Phe, Lys, His, Arg, Asp, Glu, Ala, Pro, Ser, Tyr, Met, Cys, Gly. Fasting plasma glucoses(FPG) and Fasting insulins(FINS) were detected by chemiluminescent immunoassay. HOMA-IR were calculated. The relations between 17 amino acids and FINS, FPG, HOMA-I were analyzed. 【Results】 There were serious unbalance of the distributions of 17 amino acids in the serum of patients. The levels of Met, Cys, Gly were obviously lower than those of control group(P<0.05). The levels of 14 amino acids(Thr, Val, Ile, Leu, Phe, Lys, His, Arg, Asp, Glu, Ala, Pro, Ser, Tyr) were obviously higher than those of control group(P<0.05). The distributions of Thr, His, Arg, Gly, Ala were seriously unbalanced. Although the levels of FPG of patients were normal, there were insulin resistance among the children troubled with simple obesity. There were positive correlations between FINS, HOMA-IR and Lys, Ile, Leu, Val. 【Conclusion】 In the treatment of children with simple obesity, the dynamic monitoring of serum amino acid level can help clinicians to understand the situation of imbalance in the amino acid level of the patients and to make a individual and integrative treatment plan for patients.