This study aimed to test the antibacterial activity of Bacillus cereus of actinobacterial isolates isolated from marine sponges in the Kien Giang Sea, Vietnam. That can select the strains with high resistance to identify them. There were 198 actinobacterial isolates tested. Based on the ability of antimicrobial activity to B. cereus, 82/198 had the against B. cereus, in which there were six isolates with high (7.3%), 52 medium (25.6%), and 21 weak resistance (67.1%). Selection of six isolates with the best resistance to B. cereus (ND1.7a, ND2.7c, HD1-3e, HD1-6a, HD2.3b, and H6b) identified by PCR and 16S rRNA gene sequencing. The results identified five strains of Streptomyces (Streptomyces tateyamensis ND1.7a, Streptomyces althioticus HD1.3e, Streptomyces flaveolus HD1.6a, Streptomyces olivaceus HD2.3d, and Streptomyces albidoflavus H6b) and one strain of genus Microbacterium (Microbacterium tumbae ND2.7c).