The article presents the results of studies conducted in the conditions of the mountainous zone of the Kabardino-Balkarian Republic, the studies used generally accepted methods and techniques, field and laboratory studies were carried out to study and identify the effectiveness of separate and combined use of Lignohumate AM and preparations based on biologically active substances on productivity and quality indicators of potato tubers. Potato varieties Goryanka and Nart 1 were studied as objects of research. The following preparations were the subject of research: Lignohumate AM, Polydon iodine, Fulvigrain Stimulus Pro, Zircon, BisolbiSan, Zh and Succinic acid. Analysis of the data obtained in the course of the research showed that in the variants of the combined use of Lignohumate AM and preparations based on biologically active substances, a stable high increase in potato yield was noted in all years of research. The highest increase in the yield of the Goryanka variety was noted in the variants of joint application with the Zircon preparation - 8.1 t/ha or 32.9%, of the Nart 1 variety in the variant of the combined application of BisolbiSan - 10.4 t/ha or 34.0%. The use of the drug Lignohumate AM led to an increase in the yield of varieties Goryanka and Nart 1 by 22.6% and 26.3%, respectively. In the variants of combined use of drugs, there was an increase in the content of starch and dry matter in potato tubers, respectively: in the Goryanka variety by 0.5 ... 1.3% and 0.8 ... 1.9%, in Nart 1 - by 0.7 ... 1 .1% and 0.8…1.5%. The introduction of the drug Lignohumate AM contributed to an increase in these indicators in the studied varieties from 0.7 to 1.1%