Abstract: In order to explore the effect of Maillard reaction precursors on the humus composition of dark-brown soil mixed with basswood chips,  the promoting effects of  three precursors such as  catechol (Cat),  glucose (Glu) and glycine (Gly)  in the process of humification were revealed. The indoor constant temperature culture method was used to extract and analyze the mass ratio of each humus component from the dark-brown soil mixed with basswood chips based on the addition of Cat,  Glu or Gly,  and taking sterile water as the control,   the effects of adding three different precursors on each humus component under the action of microorganisms were investigated. The experimental results show that with the increase of culture time,  the mass ratio of carbon  of water-soluble substance w（C_WSS） and total organic carbon content (TOC) of the dark-brown soil mixed with basswood chips under each treatment show a downward trend. The reduction of  w（C_WSS） in the treatment by adding Maillard reaction precursors is lower than that of CK,  and the addition of Glu can minimize the reduction of w（C_WSS） and TOC.  The mass radio of carbon of humic-extracted acid w（C_HE）of the dark-brown soil is significantly higher than that of CK in the treatment by adding  Maillard reaction precursors during the  culture period,  showing a trend of first decreasing and then increasing. After culture，  w（C_HE） slightly decreases，   and the decreasing range is greater than that of CK.  The reduction  of w（C_HA） of the dark-brown soil with the addition of Maillard reaction precursors is higher than that of CK. The additions of catechol and glycine make the molecular structure of humic acid (HA) more complicated. The Hufu ratio (w（C_HA））/w（C_FA）) of the dark-brown soil with the addition of  Maillard reaction precursors shows a trend of first increasing and then decreasing,  and finally decreases. The decrease of w（C_HA）/w（C_FA））  with Glu is lower than that of CK.  The mass ratio of carbon  of humin w（C_Hu） of the dark-brown soil under each treatment is reduced to varying degrees after the culture,  and the addition of Glu is more conducive to the mineralization and decomposition of w（C_Hu）. The addition of Glu can alleviate the loss of w（C_WSS）,  TOC and w（C_HA） of dark-brown soil，    make w（C_HE） higher than CK during the culture period,  slow down the reduction of w（C_HA）/w（C_FA）,  and be more conducive to the mineralization and decomposition of w（C_Hu） of the dark-brown soil mixed with basswood chips.

Key words: dark-brown soil, basswood chips, Maillard reaction; , precursor, humus composition