Abstract:One marine actinomycete strain FIM02-523 was isolated from marine soil in the East China Sea in Fujian Province. The fermentation broth of strain FIM02-523 exhibited potent antitumor activities. Strain FIM02-523 grew well on most media tested, the colonies were orange to dark brown but lacked aerial hyphae, no diffusible pigments were observed. Phylogenetic, chemotaxonomic, morphological analyses, physiological and biochemical characteristics demonstrated that strain FIM02-523 belong to the genus Micromonospora, may be a strain of the type species Micromonospora chalcea.