Five-hundred and eight isolates of the actinomycetes were isolated from 40 soil samples collected from various provinces of Thailand. These isolates were screened for their anti-fungal abilities using 4-plant pathogenic fungi namely, Pestalotia sp., Helminthosporium maydis, Sclerotium rolfsii and Curvularia lunata as the test organisms which were grown on solid media and found that only 3 isolates were found to have the antifungal abilities against these 4 fungi. Further screening for the antibiotic productions of these 3 isolates was also made using 3 types of liquid media namely, Sodium caseinate broth, Soybean meal broth and GMP broth. However, only 1 isolate, the No. 15 white, whose soil sample were obtained from Autaradith province was found to be the best one. The maximum yield of the antibiotic production of the No. 15 white was obtained when the culture was grown in GMP-medium with 0.5% peptone, on a rotary shaking incubator with 170 rpm at 28 degree C. Antibiotic produced by the actinomycetes No. 15 white was soluble in methanol, water, ethanol, propanol and butanol. It was stable at pH range of 1-11 at 0 degree C for 24 hours and also to heat at 100 degree C for 105 minutes. Purification of the extract by thin layer chromatography indicated that this antifungal extract was impured.