The influence of 102 compounds, mostly of solvents, at 0.1 M and 1 M (if soluble) on ligninolytic activity of Phanerochaete chrysosporirrm culture filtrates determined as the rate of veratraldehyde formation has been tested. Most of the compounds, especially the C-1 and cyclic ones, decrease the activity of lignin peroxidases. Up to a certain concentration, the decrease can be described as inhibition but not as denaturation. Most of the tested proton-donating compounds also express intrinsic activity stimulation, whereas intrinsic activity destimulation is mostly observed among proton accepters. Where available, the data of 16 solvent property parameters and experimental data were analyzed with Principal Component Analysis. The analysis showed that no single solvent property parameter correlated well with experimental data. The solvents＇ influence is complex, but hydrogen bonding and anion stabilization seem particularly important. In the homologous series of compounds, the properties represented by the intrinsic molar volume or log P also are important. Some dependencies of the effect of compounds on the structures have been established. The solvents suitable for dissolution of compounds to be treated with ligninases are suggested.