The role of antioxidants in human and animal physiology and healthcare has been good recognized owing to studies carried out for at least 50 years. In recent years, research into antioxidant properties of naturally occurring polyphenols has drawn increasing attention. In plants and soil biology impact of reactive free radicals, in particular reactive oxygen species, and the antioxidants that control them, is the subject of much recent researches aimed at understanding of mechanisms of the processes involved in soil organic matters (SOM) dynamics and of the chemical stabilization of SOM in particular. Lignins isolated from plant tissue, so called technical lignins – co-products of wood and agricultural plants chemical processing are intensively investigated as antioxidants for various materials. The main objective of this study was to investigate the radical scavenging activity of the 12 lignin preparations obtained by alkaline delignification of deciduous and coniferous wood species, agricultural plants and waste from their processing, identifying the structural features of the lignin most important for its antiradical efficiency and to search relationship between lignin antioxidant and biological activities. Rutin, epicatechin and ethanol extract from bee propolis were tested in order to assess the efficacy of lignin preparations as antioxidants. Antimicrobial effects of lignin preparations were tested using 24 isolates of soil Gram negative bacteria and 1 yeast culture. Among the technical lignins studied the highest antioxidant efficacy close to that for some plant flavonoids, applied as antioxidants in medicine and veterinary, was detected for the lignins obtained from aspen and flax. These samples could be considered as prospective polymeric antioxidants of natural origin, able to compete with low-molecular commercialized antioxidants. The antioxidant properties of technical lignins highlight their good potentials for application in the „soil-plant” system.