Torulopsis bombicola (ATCC 22214) produced sophorose lipid to 80 g/1 in batch culture containing 11% glucose and 10% soybean oil as carbon and energy sources. According to the carbon mass balance analysis, 13% and 37% of input carbon were channeled to cells and to products, respectively, and 50% of the total input carbon was channeled to CO2 gas in batch culture. In fed-batch culture with intermittent oil feeding, however, the carbon fractions incorporated into sophorose lipid and cells were 60% and 12%, respectively, and the carbon fraction evolved as CO2 gas was 30%. In conclusion, yield of sophorose lipid based on total input carbon substrates was increased from 0.37 g/g-substrate in batch culture to 0.6 g/g-substrate by employing a fed-batch culture.