In this study, a strain Xt-2 was isolated from the soil samples by E. coli induction method in Hohhot, Inner Mongolia. The strain had the similar morphological, physiological and biochemical characteristics as Myxococcus fulvus and its 16S rDNA sequence shared 99% homology with that of Myxococcus fulvus, suggesting that the strain Xt-2 belonged to Myxococcus fulvus. The analysis of antibiotic activity showed that the strain had a high resistance against phytophthora infestans and the active substances mainly existed in the extracellular metabolites of the strain. The active substances were not protein and tolerant to UV light, but sensitive to the high temperature, too acidic or too basic environment. This study laid a foundation for the extraction, separation and identification of the active substances resistant to phytophthora infestans and the further research on myxobacteria and the discovery and development of the new drugs against phytophthora infestans in Inner Mongolia area.