Abstract: ［Abstract］Objective Analyze the amino acids and acylcarnitines in the blood of patients first diagnosed with uremia using tandem mass spectrometry in order to provide a basis for clinical diagnosis and treatment. Methods 30 patients with uremia were selected as the research objects，while 15 cases of healthy person were served as the control. The values of 11 kinds of amino acids and 2 kinds of acylcarnitines in the two groups were detected using tandem mass spectrometry，and the data were analyzed and compared. Results The levels of alanine（Ala）and tyrosine（Tyr）in uremia group were significantly lower than those in control group（P < 0.05）， while the levels of citrulline（Cit），glycine（Gly）and proline（Pro）were significantly higher in uremia group than in control group（P < 0.05）. The differences were mainly in non-essential amino acids between the two groups. The levels of free carnitines and total carnitines in uremia group were significantly higher than those in normal group（P < 0.05）. Conclusion For the patients first diagnosed with uremia（not treated with replacement therapy）， the disturbance of amino acid metabolism mainly in non-essential amino acids were found in their blood，and the carnitine levels were higher than normal levels. The results could provide the basis for clinical nutrition therapy for patients with uremia.