Sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is a serious pest of many economically important crops. The insect has developed resistance to chemical insecticides. Therefore, the development of microbial agent is necessary. Among the several entomopathogenic fungi, Lecanicillium lecanii Btab01 which has high insecticidal activity was carried out this experiments. To develop mass culture, we subcultured L. lecanii Btab01 on PDA, TSA, SDA+Y, RA and GSA media at 25℃ incubator to select the optimal solid culture medium. Hyphal growth was measured every 3 or 4 days. L. lecanii Btab01 grew fastest in RA, followed GSA, SDA+Y, PDA and TSA. L. lecanii Btab01 was cultured on PDB, TSB, SDB+Y, RB, GSB media at 25℃, 180rpm shaking incubator to select the optimal liquid medium. Spore germination was measured by spread plate method every 12 or 24 hours. Spore germination appeared 7.8×108 CFU/ml after 4 days in RB, followed GSB (5.5×108 CFU/ml), SDB+Y (2.7×108 CFU/ml), TSB (1.7×108 CFU/ml) and PDB (0.6×108 CFU/ml).