Diversity of culturable actinomycetes from the Indian Ocean deep-sea sediment and the identification of the antibacterial metabolites against Gram-negative bacteria. Six compounds were identified from the fermentation broth of Erythrobacter sp. IMB16-059. Their structures were determined as cyclo(L-Pro-l-Ala)(1), cyclo(L-Pro-L-Tyr)(2), cyclo(D-Pro-L-Tyr)(3), anthranilic acid(4), thymine(5), quinolin-4(1H)-one(6). Compounds 1 and 4 showed antibacterial activity against Pseudomonas aeruginosa with inhibition zones of 1 and 20mm at 20μg/disc, respectively. Conclusion The results indicated that the deep marine sediments from the India Ocean possess diverse and abundant actinomycetesa and antibacterial activities, which could provide potential sources for the discovery of new antibiotics.