The effect of ethanol and GuHCl solution on the structure of tartary buckwheat protein(TBWSP31)was studied by UV differential absorption and fluorescence emission spectra. The alcohol denaturation of TBWSP31 was a kind of partial denaturation. The hydrophobic core of TBWSP31 remained intact and the conformation of the hydrophilic shell was changed. When TBWSP31 was denatured by GuHCl solution with higher concentration, Tyr and Trp residues were exposed to the polar aqueous solvents from the hydrophobic core, and the microenvironment showed a great change.