Abstract: Lignin is an organic polymer compound and it is most abundant renewable energy material on earth. Researches on the lignin and its derivative as the additives for the soil improvement are still at the beginning stage. The paper provides a state-of-the-art review of the application of the lignin and its derivatives as the soil improvement. Structure characteristics of the lignin, types and non-degradability are introduced in the paper. The influence of different contents of lignin and its derivatives in soil samples on the compressive strength are summarized. Effects of water stability, thermal conductivity, electrical conductivity, and pH values after mixing are comprehensively reviewed. Further studies are concentrated on the application of lignin in improving the heavy metal contaminated ionic soils. The various interactions between lignin and the soil particles are also evaluated.

Key words: lignin, mixing ratio, strength, water stability, electrical resistivity, thermal resistivity, adsorption