Abstract:The variation features of the components of organic matter in paddy soils under different thermal radiation temperatures were revealed. The results indicated that the content of dissolved organic carbon (DOC) increased initially and then reduced with the temperature rise, and a significant increase was observed at 200℃, which was 3.68-7.45 times of that of CK. Meanwhile, the neutral sugars and uronic acid showed the similar trend as DOC. Upon heating, the components and the contents of humic acids and fulvic acids in the paddy soils changed differently. The humic-to-fulvic ratio increased most at 300℃ (1.79-5.04) which indicated the humus at this temperature was less polymerized than others, whereas, the E4/E6 ratio of humic acids was maximal at 200℃, which means more aliphatic materials and low aromaticity condensation and humification degree in the soils.