The content of amino sugar-N and amino acid-N in three types of soil（black soil,brown soil and red soil） was determined by Bremner method and chromatography detection after being hydrolyzed in 6 mol.L-1HCl.The results showed that there was no significant difference in both the content and the variation between the two methods for the determination of amino sugar-N in soil.However,the content of amino acid-N in black soil and brown soil detected by liquid chromatography was significantly higher than that by Bremner method,and furthermore,less variation was found in liquid chromatography determination.The individual amino acids and amino sugars can be separated and identified in chromatography determination and this is essential to investigate the source and the transformation of soil nitrogen.