Abstract：In order to further understand the structures and properties of fulvic acid ( FA) , and to laid the foundation for the broadening the applications of fulvic acid in industrial and agricultural fields, its structure was characterized by means of Fourier infrared spectroscopy ( IR) , UV-Visible spectroscopy and13C-CP /MAS nuclear magnetic resonance ( NMR) . In addition, fluorescent properties for FA have been also investigated.The result shows that FA molecular structure is consist of aromatic nucleus and side-chain. Aromatic nucleus is mainly composed of four aromatic ring structures, and aromatic carbon is about 54%. The aliphatic carbon is about 44%, which is six-membered or five-membered of oxygen heterocycle. The content of the oxygen groups is 32. 3 % in FA, which is mainly composed of quinone and hydroxy, and a part of carboxyl group.

Keyword：fulvic acid;UV spectra;IR spectrscopy;13C CP /MAS NMR;