Objective To investigate the effect of culture condition on expressions of pertussis toxin(PT)and filamentous haemagglutinin(FHA)in fermentation process of Bacillus pertussis. Methods B. pertussis was subjected to fermentation culture with S-S medium in fully automatic 300 L fermenter in ventilation. The volume, temperature, time and MOI for culture were 200 L, 35 ∼ 37 °C, 40 h and 1 : 12 ∼ 1 : 15 resp. The test was performed in three groups, three batches for each. The stirring speed in high PT expression group was 160 r/min, while straight mixing blade with baffle was adopted, and the ventilation volumes for culture for 0 ∼ 20 and 21 ∼ 40 h were 600 and 400 L/min resp. In high FHA expression group, the stirring speed was 220 r/min, while curved mixing blade without baffle was adopted, and the ventilation volumes for culture for 0 ∼ 20 and 21 ∼ 40 h were 400 and 600 L/min resp. However, in control group, the stirring speed was 180 r/min, while straight mixing blade with baffle was adopted, and the ventilation volume was 500 L/min. The PT and FHA contents were determined by ELISA after completion of culture. Results The mean expression level of PT in high PT expression group was 3. 16 μg/mL, which was 41. 7% higher than that in the control group(2. 23 μg/mL)(P < 0. 05). However, the mean expression level of FHA in high FHA expression group was21. 37 μg/m L, which was 94. 3% higher than that in control group(11. 00 μg/mL)(P < 0. 05). Conclusion In the fermentation process of B. pertussis, high stirring shear force and low dissolved oxygen(DO)level were beneficial to the PT expression, while low stirring shear force and high DO level were beneficial to increase of yield of FHA.