The dynamic of endophytic bacteria at different growth stage of tomato and use of these endophytic bacteria to control tomato bacterial wilt were studied. The results showed that endophytic bacteria could be found in the tomato seeds and their quantities reached the highest peak in the adult plants both in resistant and susceptible cultivars. The amount of endophytic bacteria in adult plants of resistant tomato cultivars was 2.43×10⁵CFU/g FW in the root and 22.9×10⁴ CFU/g FW in the stem, while the amount of endophytic bacteria in adult plants of susceptible tomato cultivars was 9.8×10⁴CFU/g FW in the root and 13.4×10⁴CFU/g FW in the stem respectively. Seventeen strains of endophytic bacteria from resistant cultivars and only seven strains from susceptible cultivars were found to be antagonistic to Ralstonia solanacearum. In addition, some strains of endophytic bacteria had the abilities of promoting tomato seed germination and controlling tomato bacterial wilt, among which, strain 5R and 3R had better control effect of 91.7% and 81.3% respectively.