[en] This research was aimed to study the effect of ethyl acetate extracts from Streptomyces diastatochromogenes KX852460 on action mechanism at various stages of life cycle of Rhizoctonia solani AG-3, such as sclerotia, mycelium, basidiospores and hyphae. Suppression of sclerotia and mycelium was determined by measuring the inhibition zones. While morphology of mycelium and hyphae formation were observed by scanning electron microscopy and transmission electron microscopy, respectively, the basidiospores formation and ROS generation were detected by confocal laser scanning microscopy. Extract from S. diastatochromogenes KX852460 had 96% inhibition effect against the mycelium, formation of the sclerotia decreased from 71.73 to 0% as the concentration of the treatment increased from 1 × 10⁻⁴ to 7 × 10⁻⁴ mM and 88.22–97% inhibition effect on disease lesion. Suppression of basidiospores was one of the significant approaches evidenced by visualization using confocal laser scanning microscopy. Scanning electron microscopy analysis showed changes in morphological attributes of R. solani AG-3 caused by ethyl acetate extract of bacteria. Transmission electron microscopic observation revealed suppression of hyphae. Generation of endogenous ROS and oxidative damage were evidenced by the confocal laser scanning microscopy. Ethyl acetate extracts from Streptomyces diastatochromogenes KX852460 exhibited potential antagonistic action against the R. solani AG-3 at various stages of its life cycle including sclerotia, mycelium, basidiospores and hyphae which could be utilized as biocontrol agent.