Abstract: The purpose of this study is to screen microorganisms with growth inhibition against plant fungal pathogens. The plate-dilution method was used to isolate the bacteria from salt marshes at Dafeng, Jiangsu. The antifungal activity of the bacterial broth filtrates against 5 phytopathogens was determined using mycelial disk method. The antifungal compositions of four active bacteria were analyzed primarily with chromatography techniques. Two hundred and thirty-five aerobic (92) and anaerobic (143) bacterial strains have been isolated from the coast salt marsh and sixty-five strains, of which 39 are aerobic and 26 are anaerobic showed greater than 30% of inhibition rate against the growth of at least one of the phytopathogenic fungi on petri dish. Three aerobic and one anaerobic strain representing four different spectra of antifungal activities were selected to do large scale fermentation. The fermentation broths were fractionated and purified with different methods resulting in some antifungal components. To be concluded, coast salt marshes are rich in bacteria；about 28% of them show potential ability to produce antifungal substances. Particularly, strain Y6 ,Y156 and Y78 are worthy to be developed because of the water soluble nature of their active substances.