A continuous countercurrent extraction process for the recovery of hydrocortisone from the fermentation liquor has been developed with annular centrifugal contactors. When the hydrocortisone was extracted from the fermentation liquor with the butyl acetate, the distribution ratio increased with increase of the hydrocortisone concentration in the equilibrium aqueous phase. Both the laboratory tests and the plant tests have been finished with Phi 20 mm and Phi 230 mm annular centrifugal contactors respectively. In the laboratory tests, when the rotor speed was 3400 similar to 4200 r/min, the fermentation liquor flow was 30 similar to 50 mL/min and the phase ratio (V O /V A ) was 0.36 similar to 0.50, the percent recovery of hydrocortisone was higher than 92%. In the plant tests, when the rotor speed was 2000 r/min, the fermentation liquor flow was 2000 L/h and the butyl acetate flow was 1000 L/h, the percent recovery of hydrocortisone was about 96.5 similar to 98%.