Response surface methodology was employed to optimize the composition of medium for the production of resistomycin by Streptomyces aurantiacus AAA5 in submerged fermentation. Cassava pulp, soybean meal and potassium nitrate were found to have significant effects on resistomycin production by Plackette Burman followed by Box Behnken design. A mathematical model was developed to identify the optimum concentration of key nutrients for higher resistomycin production. A quadratic model was found to fit the resistomycin production. The analysis revealed that the optimum values of the tested factors were 1.54g soybean meal, 10.39% cassava pulp and 1.3g potassium nitrate yielded 193.4 mg/L of resistomycin. A production of 194.3 mg/L which was in agreement with the prediction was observed in verification experiment. In comparison to the original production level, 3.7 fold increase had been obtained.