Cryogenic　temperature　is　one　of　the　extreme　environments　for　the　application　of　concrete.　Compared　with　the　vast　amounts　of　researches　on　the　size　effect　of　concrete　at　ambient　temperature,　the　investigation　on　size　effect　at　cryogenic　temperature　is　very　limited.　This　work　presents　a　series　of　experimental　investigations　on　the　static　uniaxial-compressive/　splitting-tensile　failure　of　concrete　with　different　structural　sizes　(100,　150,　and　300　mm)　at　four　target　temperature　levels　(+20　degrees　C,　-30　degrees　C,　-60　degrees　C,　and　-　90　degrees　C).　The　experimental　results　indicate　that　when　the　temperature　decreases,　the　concrete　specimens　present　more　brittle　failure　patterns　and　the　number　of　damaged　aggregate　particles　on　the　failure　surface　increases.　Additionally,　both　the　measured　uniaxialcompressive　and　splitting-tensile　strengths　increase　linearly,　and　structural　size　exhibits　a　significant　influence　on　the　nominal　strengths.　The　obvious　size　effect　can　be　observed　on　compressive　and　splitting-tensile　strengths　at　cryogenic　temperature.　Compared　to　uniaxial-compressive　strength,　cryogenic　temperature　performs　more　significant　effect　on　the　splitting-tensile　strength　and　its　corresponding　size　effect.　Finally,　based　on　the　statistical　size　effect　law,　a　modified　prediction　formula　considering　quantitative　coupling　effect　of　temperature　and　structural　size　was　proposed,　which　can　predict　the　nominal　strength　of　concrete　with　different　structural　size　at　different　cryogenic　temperatures.