Abstract: Special habitat actinomycetes have great development prospects because their unique living environment can produce novel and biologically active secondary metabolites. The secondary metabolites of Streptomyces plumbidurans were studied, and small molecular compounds with antitumor and antimicrobial activities were searched. The secondary metabolites were isolated by Sephadex LH-20 column chromatography, D101 macroporous resin, and RP-18 reverse-phase column chromatography from the EtOAc extract of the culture of Streptomyces plumbidurans. The structures were characterized by various spectroscopic (¹H NMR, ¹³C NMR and MS) and comparison with the data of literatures. MTT method and microdilution method were used to test the antitumor activity in vitro and antimicrobial activity of the above compounds. Three new compounds identified as kcacylamide A ( 1 ), kcacylamide B ( 2 ) and kcacylamide C ( 3 ). Compounds 1 − 3 did not show significant activity at the concentration of 50 μmol/L. In this study, we found that Streptomyces plumbidurans could produce acylamide compounds for the first time.