Abstract: Tagged by the resistance to Rif.(300μg/ml) and the plant pathogen, the colonization of the endophytic marine bacterium CⅢ-1,isolated from Bruguiera gymnorrhiza, in plants was tested with seed dipping, leaf daubing and root watering. The result showed that this strain could colonize in many plants, such as capsicum, tomato, eggplant, cabbage, lettuce, cowpea, wheat, corn and rice. The colonization dynamics of the strain in the capsicum showed that the bacterial density of the strain in the capsicum and its rhizosphere soil varied with different inoculations, and it was more easily to colonize in the leaf and rhizosphere soil than in the stem, and the colonization duration in the leaf and rhizosphere soil lasted for 10d~15d.