With　extremely　bad　climate　and　poor　geographical　environment　in　cold　and　arid　region,　the　deterioration　and　failure　of　road　materials　are　serious.　In　order　to　analyze　the　characteristics　of　natural　aging　behavior　of　asphalt　binder　in　cold　and　arid　region,　the　experiments　were　carried　out　based　on　the　exposure　field　test　base.　The　multiscale　characterization　of　virgin　asphalt　under　different　natural　aging　conditions　was　carried　out　by　means　of　macromechanical　analysis　and　microchemical　composition　analysis.　The　results　showed　that　the　effects　of　natural　aging　and　laboratory　simulated　aging　on　asphalt　binder　properties　were　similar.　There　was　little　effect　on　the　performance　of　asphalt　binder　after　natural　aging　one　year.　The　effect　of　natural　aging　on　asphalt　binder　in　one　year　was　similar　to　that　of　laboratory　short-term　aging.　However,　the　strong　UV　radiation　was　a　great　challenge　for　asphalt　pavement　in　Northwest　China.　Wind,　dust,　rain,　and　other　factors　have　little　effect　on　asphalt　binder　aging.　Affected　by　the　natural　environment,　macromolecular　structures　such　as　oxygen-containing　polar　functional　groups　will　form　in　asphalt　binder.　The　molecular　weight　of　asphalt　binder　was　increased,　and　the　internal　molecules　of　asphalt　binder　were　subjected　to　large　internal　friction　resistance　in　the　process　of　movement.　The　macroscopic　physical　properties　and　road　performance　of　asphalt　binder　become　poor.