The anti-aging effects of four Bifidobacterium species (B. pseudospermum BP-1, B. longum BL-3, B. animalis BA-5 and B. infantis BI-38) on Caenorhabditis elegans were evaluated in terms of its lifespan, reproductive capacity, vitality, body shape, stress resistance, lipofuscin levels, antioxidant enzyme activity and malondialdehyde (MDA) content. The results showed that compared with the control group (Escherichia coli OP50), BA-5 and BI-38 effectively extended the lifespan of C. elegans (P < 0.05), while BP-1 and BL-3 had no significant effect on the lifespan of C. elegans (P > 0.05). Meanwhile, BA-5 and BI-38 did not impair the reproductive or locomotory capacities of C. elegans (P > 0.05), but could effectively enhance its pharyngeal pumping and reduce its body size (P < 0.05). BA-5 and BI-38 were able to enhance tolerance to heat or oxidative stress and thus prolong the lifespan of C. elegans (P < 0.05), significantly reduce lipofuscin accumulation and MDA content (P < 0.05), and significantly increase the activity of two antioxidant enzymes (catalase and superoxide dismutase) in C. elegans (P < 0.05). In conclusion, B. infantis BI-38 and B. animalis BA-5 had stronger anti-aging activity in vivo.