In　this　paper,　the　styrene–butadienestyrene　(SBS)　modified　bitumen,　recycled　polyethylene　(RPE)　modified　bitumen　and　their　base　bitumen　are　aged　by　thermal　oxidative　aging　and　all-weather　aging　tests.　The　fluorescence　microscopy　(FM),　thin　layer　chromatography,　gel　permeation　chromatography,　infrared　spectroscopy　and　dynamic　shear　rheometer　are　used　to　trace　the　chemo-rheological　and　morphology　evolution　of　various　aged　bitumens.　FM　observation　and　chemical　investigation　show　that　the　leading　role　of　polymer　degradation　and　bitumen　oxidation　in　various　aging　stages　is　different.　SBS　structures　are　mainly　degraded　at　the　short-term　aging　stage,　while　the　oxidation　of　RPE　bitumen　in　short-term　aging　process　is　more　prominent　than　its　polymer　degradation　due　to　its　poor　compatibility　and　dispersion.　The　bitumen　oxidation　becomes　the　leading　process　of　long-term　aging　and　all-weather　aging　for　bitumens.　Furthermore,　the　multi-scale　analysis　reveals　that　the　all-weather　aging　imparts　the　far　more　pronounced　impacts　to　the　chemical　and　rheological　properties　of　base　bitumen　and　RPE　bitumen　than　long-term　aging,　while　SBS　bitumen　is　more　affected　by　long-term　aging.　Moreover,　SBS　bitumen　has　much　more　excellent　aging　resistance　to　the　transitions　of　chemo-rheological　properties　than　RPE　bitumen　and　subsequent　base　bitumen.　Especially,　the　deep　effect　of　all-weather　aging　is　analyzed　by　comparing　the　chemical　variations　of　bitumens　at　different　sampling　depths.　Results　illustrate　that　the　all-weather　aging　almost　runs　through　the　entire　depth　of　base　bitumen.　In　contrast,　SBS　spatial　reticular　structures　can　significantly　mitigate　the　oxidation　depth　of　SBS　bitumen,　whereas　the　mitigation　effect　of　RPE　bitumen　on　all-weather　aging　is　weakened.　©　2020　Elsevier　Ltd