Abstract: The present invention relates to a composition for life extension, comprising reduced coenzyme Q10 as an active ingredient, as well as relates to a method of extending a life span using the composition comprising reduced coenzyme Q10 as an active ingredient. In the present invention, it has been found that long-term ingestion of feed that contains reduced coenzyme Q10 enables the life span of senescence-accelerated model mice to be extended. No sign indicating toxicity is observed in the senescence-accelerated model mice that have been fed with reduced coenzyme Q10 over a long period. Based on these findings, it was found that the composition containing reduce coenzyme Q10 as an active ingredient has potential to be a composition for life extension with high safety, capable of being taken for a long period.