The sample preparation conditions are optimized to obtain the matrix assisted laser desorption/ionization mass spectra of lignin. Ionic liquids are proposed as effective matrices, capable to dissolve the natural polymer. It is shown that the best results can be obtained using ionic liquids based on trialkylammonium salts of aromatic acids. The obtained mass spectra of different lignin preparations demonstrate the presence of wide peaks at the distance corresponding to molecular mass of lignin macromolecule structure fragments (196 Da for coniferous lignins) and a thin structure - a number of peaks with ∆ m/z of 14 and 16 Da relevant to methylene groups and oxygen.