Cold　stress　adversely　affects　cell　viability　and　acidification,　and　new　cryoprotective　methods　continue　to　be　needed　in　cold-chain　food　industry.　Given　this,　we　investigated　the　cryoprotective　effects　and　action　mechanism　of　antifreeze　peptides　obtained　from　tilapia　scales　(TSAPP)　on　Streptococcus　thermophilus　during　cold　stress.　Our　results　showed　that　the　molecular　weight　of　TSAPP　ranged　from　180　to　2000　Da　and　its　thermal　hysteresis　activity　was　0.29　°C.　Growth　of　S.　thermophilus　was　improved　after　treatment　with　TSAPP　(1　mg/mL)　under　cold　stress.　This　growth　was　notable　when　compared　with　the　effects　of　other　cryoprotectants.　Furthermore,　TSAPP　improved　the　metabolic　activity　of　S.　thermophilus　during　cold　stress.　TSAPP　likely　offered　its　cellular　protection　by　maintaining　cell　membrane　fluidity　through　hydrogen　bonding　of　the　phospholipid　bilayer.　These　results　indicate　that　TSAPP　has　potential　as　a　novel　biological　peptide　material　with　cryoprotective　activity　for　future　use　in　probiotic　or　other　processed　food　applications.　©　2019　American　Chemical　Society.