In the article are exposed the results of the study of microbiological and biochemical quality of biocopmpost  obtained by using the effective microorganisms from microbial preparations „Baikal ЭМ-1” and „EM-1”, in the process of bioconversion of the organic wastes.The purpose of the research included the determination of the role of efficient microorganisms in the process of processing of organic wastes. The objective of the researchers was to determine the influence of efficient microorganisms on the process of processing of organic wastes and the quality of the biocompost obtained.For the purposes of the researchers, were purchased two preparations concentrated by efficient microorganisms "ЭМ Baikal-1" and "EM-1" from which the basic solutions were obtained, by dilution with unchlorinated water and by filtration. Analyzing the results obtained in the experiment, it was found that in biocompost obtained from the unfermented manure of cattle, subjected to the bioconversion process using preparation „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. The results of the microbiological investigations, it was found that the use of the "Baikal ЭМ -1" preparation in the bioconversion process resulted in an escalation of bacteria in the genus Bacillus (from 1.1×108 to 1.4×1012 cm/g) and concomitant decrease of 10-100 times the amount of E. coli and fungus Candida genus. At the same time, the composition and amount of microorganisms studied in the unfermented manure subjected to the influence of the preparation "EM-1" they have changed insignificantly. 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. Thus, as a result of microbiological and biochemical researches performed to evaluate the influence of ME on biohumus quality, changes in the essential growth of bacteria in the genus Bacillus have been observed, decreasing from 10-100 times the amount of E. coli and fungi from the Candida genus, also reduced the amount of ammonia and increased the total nitrogen content