Root rot is a serious disease on fruit tree, wspecially on citrus in the Mekong Delta. The main reason cause rot root disease is Phytophthora spp. and Fusariun solani. Avaluate ability to inhibite of 14 bacterial antagonist strains on Phytophthora palmivora and Fusarium solani showed that there are 2 strains BS and VK2 ability resistance well both Phytophthora palvora and Fusariun solani. Also, for Phytophthora palmivora, 199, VK3 and PS5 bacterial strains has good resistance in vitro.