A study was carried out to screen 25 Actinomycetes isolates that have ability to act as biocontrol agents Actinomycetes against Ganoderma sp. TB3 and Ganoderma sp. TB4. Among 25 Actinomycetes isolates, only Actinomycetes SM12 can inhibit the growth of both Ganoderma sp. TB3 (52 %) and Ganoderma sp. TB4 (60 %). Antagonistic assay using cross streak method with a longer period of delayed antagonism showed higher inhibition effect to the growth of Ganoderma sp. TB3 (76 %) and Ganoderma sp. TB4 (85 %). Identification of Actinomycetes SM12 based on 16S rRNA revealed that Actinomycetes SM12 belong to Streptomyces cellulosae. The Actinomycetes SM12 isolate produces rectinaculum-apertum spore chain and forms a colony that exhibited white to greyish color. Enzyme activity test showed that the cultures are positive in amylase, protease, lipase and cellulase production respectively.