The paper presents data on the intensity of lipid peroxidation processes in the leaves of Vaccinium myrtillus L. (family Ericaceae Juss.) under various ecological and cenotic conditions. The studies were carried out in the growing season of 2022 in forest phytocenoses with the participation of V. myrtillus in the grass-dwarf shrub layer within the forest-park green belt of the city of Kirov (southern taiga subzone). The activity of lipid peroxidation was assessed by the content in the leaves of products that react with thiobarbituric acid. It has been established that the intensity of lipid oxidation processes, which was determined by the accumulation of malonic dialdehyde, in spruce forests is characterized by lower values (0,026-0,028 mmol/g wet weight), compared with pine forests, where its concentration in leaves reached 0,031 mmol/g wet weight masses. The results of the correlation analysis indicate a high positive relationship between the intensity of malondialdehyde accumulation and illumination (r=0,90, at p≤0,05) in the habitats of V. myrtillus and a negative correlation (r=-0,90, at p≤0,05) between the concentration of malonic dialdehyde and the richness of soils in nitrogen in the considered biotopes. The obtained results indicate that in more illuminated and nutrient-poor ecotopes, which correspond to the habitat conditions of the species in pine forests, the processes of formation and accumulation of malondialdehyde are activated, compared with spruce forests, for which changes in the content of malondialdehyde during the vegetation periods under consideration are less significant.