Objective: To establish liquid chromatography-mass spectrometry (LC-MS) method for content determination of amino acid and nucleoside in Semen Sojae Praeparatum from different origins. Method: The contents of 22 amino acids and 16 nucleosides in 8 bathes of Semen Sojae Praeparatum (collected from Anhui

Jiangsu and Henan provinces) were determined by an ultra fast liquid chromatography coupled with triple quadrupole mass spectrometer. Waters XBridge Amide column (2.1 mm×100 mm

3.5 μm) was used with 0.2% formic acid acetonitrile-0.2% formic acid solution as the mobile phase for gradient elution at a flow rate of 0.6 mL·min-1. In addition

electrospray ionization and multiple reaction monitoring (MRM) mode were used. The results were used for PCA-DA cluster analysis and t test. Result: The 22 amino acids and 16 nucleosides in Semen Sojae Praeparatum were well separated

and showed good linear relationship between concentration and peak area. The average recovery rate was between 93.74% and 104.32%

RSD 0.6%-3.5%. There were significant differences in the amino acids and nucleosides contents among different batches. The total contents of amino acids were at 7.241-34.21 mg·g-1

and the total contents of nucleosides were at 14.21-82.53 mg·g-1. The contents of amino acids were in the following order from high level to low level:Anhui > Jiangsu > Henan

and nucleosides were in the following order from high level to low level:Jiangsu

Anhui > Henan. The total contents of amino acids and total contents of nucleosides in samples with shorter storage time were higher than those with longer storage time in the same region. Conclusion: This method is applicable for the simultaneous determination of contents of 38 kinds of amino acids and nucleosides. The differences in the study can fill up the blank in Semen Sojae Praeparatum from different origins reflect the quality of samples from different origins

and provide references for the further pharmacodynamic research.