Shell-side　two-phase　pressure　drops　under　cross-flow　condition　play　an　important　role　in　the　operation　of　heat　exchangers.　However,　no　well-verified　general　correlation　for　predicting　two-phase　friction　multipliers　in　horizontal　tube　bundles　is　available　in　the　open　literatures.　In　the　present　paper,　based　on　a　combination　of　Kanizawa　and　Ribastki　flow　regime　criteria　with　the　modified　Mao　and　Hibiki　flow　regime　criteria,　the　flow　patterns　of　two-phase　vertically　upward　flow　across　horizontal　tube　bundles　in　the　open　literatures　were　identified.　The　results　show　that　flow　patterns　have　a　significant　effect　on　two-phase　friction　multipliers.　For　the　bubbly　flow,　finely　dispersed　bubbly　flow,　and　annular　flow,　the　mass　velocity　effect　on　two-phase　friction　multipliers　can　be　neglected.　However,　the　two-phase　friction　multipliers　of　cap　bubbly　flow　and　churn　flow　decrease　with　an　increasing　mass　velocity.　Then,　a　general　dimensionless　correlation　in　terms　of　the　Martinelli　parameter　and　the　two-phase　Froude　number　were　developed,　which　is　able　to　accurately　predicting　gas-liquid　two-phase　flow　resistances　of　churn　flow　in　staggered　horizontal　tube　bundle　under　cross-flow　condition.　New　correlations　for　predicting　two-phase　friction　multipliers　of　bubbly　flow,　finely　dispersed　bubbly　flow　and　annular　flow　both　in　staggered　and　in-line　horizontal　tube　bundles　were　also　developed　and　can　give　excellent　representations　for　the　existing　data　in　the　open　literatures.　(C)　2018　Elsevier　Ltd.　All　rights　reserved.