Effect of the steroidal saponins of Fructus tribuli on growth of Lactobacillus acidophilus LA04, LA05 and LA06 was studied by measuring optical density at 600 nm (OD_(600)) and pH using MRS media as the control. The addition of steroidal saponins (w/v) was 0.05, 0.10, 0.15, 0.20 and 0.25%, respectively. Results were as follows: addition of steroidal saponins of Fructus tribuli could promote the growth of Lactobacillus acidophilus LA04, LA05 and LA06 and the optimum concentration of steroidal saponins was all 0.25% for the three strains.