Bio-based　materials　can　be　used　as　alternatives　to　raw　asphalt　and　its　modifiers,　contributing　to　reduce　the　dependence　of　asphalt　pavements　on　non-renewable　resources.　Four　bio-based　materials　(chitosan,　cashew　nut　shell　liquid,　lignin,　and　quercetin)　were　selected　as　modifiers,　and　were　combined　with　isocyanate　pre-polymers　to　modify　asphalt,　preparing　bio-based　polyurethane-modified　asphalt　in　this　work.　And　the　effects　of　different　bio-based　materials　on　the　physical-rheological　properties,　fatigue　resistance,　and　aging　resistance　of　polyurethane　modified　asphalt　were　systematically　investigated.　Research　results　indicate　bio-based　polyurethanemodified　asphalt　exhibits　superior　high-temperature　performance　compared　with　common　polyurethanemodified　asphalt,　with　quercetin-polyurethane　modified　asphalt　performing　the　best.　The　introduction　of　biobased　materials　improve　the　fatigue　resistance　and　toughness　of　polyurethane-modified　asphalt.　All　four　biobased　materials　can　significantly　enhance　the　aging　resistance　of　modified　asphalt,　lignin　shows　the　best　performance.　Compared　to　common　polyurethane　modified　asphalt,　the　rutting　factor　aging　index　and　sulfoxide　index　growth　rate　of　lignin-based　polyurethane　modified　asphalt　decrease　by　78　%　and　92　%,　respectively.　This　research　offers　theory　and　data　for　bio-based　polyurethane-modified　asphalt　design,　promoting　green　road　material　development.