In order to obtain tofu coagulator of high quality, investigated the titratable acidity and antioxidant activities of the fermented tofu whey by 3 strains of Lactobacillus amylolyticus L5, L6 and Pichia amethionina Y, which were separated and purified from natural fermented tofu whey, with the single, double and three strains as starters. The results indicated that both of the Lactobacillus were able to grow and produce acid in the tofu whey, the titratable acidity of fermented tofu whey by L6 for 60 h reached 65.11 ^oT at the temperature of 35 ℃, displaying a better capacity in producing acids, while, it also reached 65.44 ^oT when the tofu whey was fermented by the starter of L5+L6+Y under the same condition. The ability of reducing Fe³⁺ and scavenging DPPH radical of fermented tofu whey by L6 increased slightly, but the power of iron(II)-chelating significantly enhanced, with the power of 54.45%. In contrast, the power of iron(II)-chelating of fermented tofu whey by L5 decreased with the increasing fermentation time. The abilities of producing acids, reducing Fe³⁺, iron(II)-chelating and DPPH radical scavenging of fermented tofu whey by L5+L6+Y were strong than those by L6+Y. In summary, Lactobacillus amylolyticus L6 was the best strain to produce acid and antioxidant activities in tofu whey among the 3 single strains, while, L5+L6+Y was the best combination among the multi-strain starters.