A two-factor field experiment with white lupin cv. Butan was carried out. The first factor was the green forage harvest date (the flat pod stage – Cut 1 and the stage of green ripe seeds – Cut 2), while the second one – application of silage additives: biological (strains of lactic acid bacteria) and chemical (a mixture of organic acids), and the control treatment (without additives). In Cut 2 higher fresh matter (FM) and dry matter (DM) yields were obtained. Silage inoculated with the biological additive contained a significantly greater count of lactic acid bacteria. Both additives reduced counts the Clostridium bacteria, yeasts and mould fungi. The silage with the chemical additive had a three-fold higher content of water-soluble carbohydrates (WSC), while the biological additive increased lactic acid (LA) levels. White lupin can be used as a silage raw material, but plants before ensiling should be partially wilted and silage additives should be applied