Ten actinomycetes strains from inter-tidal marine sponge Hymeniacidon perleve of China Yellow Sea were isolated and bio-assayed for antibiotic activities.3 of the 10 strains displayed antimicrobial activity when in monoculture.While strain Hp-053 was co-cultured with each of the other 9 strains,5 of the 9 co-cultures exhibited enhancing antimicrobial activity.TLC results and bio-autography of extracted samples indicated that chemical compounds and antimicrobial compounds produced by co-cultures of sponge associated actinomycetes were different from those by monoculture.Co-culture induction may be a valuable novel tool for the exploitation of sponge associated microorganism.