With the aim of obtaining the high producing strain of epothilones B, we mutated Sorangium cellulosum SoF5-76 with the combination treatment of UV rays and N-Methyl-N’-Nitro-N-Nitrosoguanidine (NTG) to improve the yields. Epothilone B yield was improved from 35.24mg/L to 79.83 mg/L of the broth resulting in a high yielding mutant. Then, Plackett-Burman design and the response surface methodology (RSM) were applied to optimize fermentation process of the high producing mutant. The obtained optimal fermentation conditions were potato starch 4.8 g / L, skim milk powder 2.3g / L, glucose 0.5g / L, soybean powder 2g / L, magnesium sulfate 2g / L, chlorine calcium 2g / L, EDTA-Fe^{3 +} 2mL / L, trace elements 0.5mL / L, absorbent resin 2%, pH7.4, liquid volume 50mL/250mL, inoculation amount 8%, temperature 30°C. Under this optimal condition, epothilone B production reached up to 108.67mg / L that was 36.13% higher than preliminary conditions. It is the higher yield of epothilone B in the epothilone producing strains reported in literatures.