Continuous flow technique was used to study the formation of organic acids and of carbon dioxide during anaerobic breakdown of glucose in soil. Carbon dioxide, formic, acetic, butyric and lactic acids were the main products of anaerobic decomposition of glucose. However, succinic acid, α-ketoglutaric acid and fumarie or glutarie acids could be detected also under certain circumstances. Two types of glucose fermentation apparently occurred during continuous addition of glucose to the soil. The mixed acid fermentation of glucose prevailed at the later stage. Simultaneous addition of mineral nitrogen and phosphorus with glucose stimulated the conversion of organic acids to methane in soil exhibiting high capacity of methane-forming bacteria.