Abstract : Serratia symbiotica, one of the most frequent symbiont species in aphids, includes strains that exhibit various lifestyles ranging from free-living to obligate in-tracellular mutualism. Here, we report the draft genome sequences of two strains, namely, 24.1 and Apa8A1, isolated from aphids of the genus Aphis, consisting of ge-nome sizes of 3,089,091 bp and 3,232,107 bp, respectively. These genome sequences may provide new insights into how mutualistic interactions between bacteria and insects evolve and are shaped.