From research on the use of chiral ionic liquids with a natural origin substituenl for wood proteclion. Antifungal activities of chiral ionic liquids - menthoxymethylimidazolium derivates against brown-rot decay fungus (Coniophora puteana), white-rot decay fungus (Trametes versicolor) and blue-stain fungus (Sclerophoma pithyophila) were determined using screening agar-plate and agar-block methods. Results from antifungal tests revealed that 1-hexyl-3-[(1R,2S,5R)-(-)menthoxymethyl]imidazolium chloride exhibited the strongest antifungal activity against wood decay fungi (basidiomycetes) compared with the commercial didecyldimethylammonium chloride. Whereas compound with twelve carbons alkyl substituent has a weak antifungal activity. The infrared spectral analysis (FTIR ATR) confirmed that chiral imidazolium ionic liquids were built into the structure of the treated wood.