Bioassay-guided fractionation of the EtOAc extract of a marine Bacillus sp. Sc026 culture broth has led to the isolation of the known compound, macrolactin F (1), together with two new compounds, 7-O-succinyl macrolactin F (2) and 7-O-succinyl macrolactin A (3). The chemical structures of 1-3 were elucidated on the basis of spectral data analyses and literature data comparison. Compounds 1-3 exhibited antibacterial activity against Bacillus subtilis and Staphylococcus aureus.