Obtaining organic agricultural production is a matter of global importance for society. The global environmental situation, including the regional, has worsened in the last century due to the industrialization and chemicalization of agriculture, the storage, preservation and unreasonable use of organic waste, etc. These have resulted in pollution of the environment and its components. A special role in the improvement of the environmental situation belongs to the technology of bioconversion of organic waste using biological methods (worm cultivation technology). Effective microorganisms were discovered by Teruo Higa, professor at Ryukyus University in Okinawa (Japan) in 1980. The technology of effective microorganisms opens new perspectives and opportunities for sustainable agriculture. It can become the basis for efficient production of organic products of plant and animal origin. In the article are reported the results of the study of biochemical quality of biocompost obtained by using the effective microorganisms from microbial preparations „Baikal ЭМ-1” and „EM-1”, in the process of bioconversion of the unfermented organic wastes. The purpose of the research was to determine the influence of microorganisms on the processing of unfermented organic waste and the quality of the compost obtained. For the research purpose, two microorganism concentrates “Baikal ЭM-1” and “EM-1” were diluted in a ratio of 1:100 using unchlorinated and filtered water, having a temperature of 20-25°C and with the addition of molasses nutrient solution. The working solution was obtained by multi-stage process and subsequently used for the processing of unfermented cattle manure. For processing 0.5 tons of manure, were used 50 liters of working solution. The process of manure processing with the preparation „Baikal ЭM-1” was performed under anaerobic conditions and with the preparation „EM-1” under aerobic conditions. The biochemical investigations of unfermented cattle manure and compost obtained after 2 months of microorganism processing have been performed according to the methods set forth in the Standards (ГОСТ 26204-84-262013-84, 1984 and ГОСТ 26712-94, 1994) and specialized textbooks (Petuhova E.A. et al., 1989, Popov A. В. et al., 1973, Razumov B.A., 1986). Analyzing the experimental results it was found that in biocompost obtained from the unfermented manure of cattle, subjected to the bioconversion process using preparations „Baikal ЭМ-1” and „EM-1” diminished essentially the content of ammonia, respectively with 79.68% - 70.91% and 85.09% - 70,03%, and increased the total nitrogen, respectively with 147.33% - 105.33% and 162.67% - 128.00% in comparison with the same indicators in manure samples at the initial stage. Consequently, it has been found that use „Baikal ЭМ-1” and „EM-1” preparations has led to substantial changes in content ammonia and total nitrogen, thus improving the quality of the biocompost.