The genus Bacillus of gram-positive spore-forming bacteria has produced biologically active compounds [1, 2]. During the course of our search for bioactive natural products from the bacterium Bacillus amyloliquefaciens collected from South China Sea deep-sea sediment, we have reported two cyclic tetrapeptides 3. Further investigation on the culture broth of this bacterium has led to the isolation and characterization of a new alkaloid, halomide (1). We describe herein the isolation, structure elucidation, and toxicity of compound 1.