High　viscosity　modified　asphalt　(HVMA)　was　the　core　material　to　build　ecological　permeable　pavement,　while　it　was　prone　to　aging,　which　limited　its　applications　for　urban　sustainability.　This　study　focused　on　the　oxidation　and　polymer　degradation　characteristics　of　the　high-content　styrene-butadiene-styrene　modified　asphalt,　high-viscosity　composite　particle　modified　asphalt　and　high-elastic　modified　asphalt　under　the　simulated　aging　environments　of　thermal　oxidation　and　weather.　Gel　permeation　chromatography　results　showed　that　the　increase　percent　of　large　molecular　size　percent　and　the　decrease　percent　of　polymer　weight　could　characterize　the　oxidation　degree　and　polymer　degradation　degree,　respectively.　The　degrees　of　oxidation　and　polymer　degradation　in　all　HVMAs　increased　synchronously　with　aging,　and　reached　the　highest　after　the　weather　aging.　The　polymer　molecular　distribution　of　HVMA　would　become　more　uniform　with　aging　from　the　proposed　ratio　of　polymer　weight　to　polymer　content.　Dynamic　shear　rheometer　tests　reflected　that　there　existed　the　dual　effects　of　coupling　and　parallelism　during　aging　of　HVMA,　i.e.　the　oxidation-induced　hardening　effect　and　degradation-induced　softening　effect.　Furthermore,　the　change　percent　of　rheological　indicators　was　proposed　as　the　net　aging　degree.　Considering　the　rheological　properties　of　aged　HVMA　were　the　coupling　results　of　dual　effects,　the　net　aging　degree　could　represent　the　oxidation　dominance　degree　or　polymer　degradation　dominance　degree　of　HVMA.　Due　to　the　differences　of　dual　effects　and　polymer　molecular　distribution,　various　HVMAs　showed　the　totally　different　net　aging　degree　ranking,　depending　on　the　aging　states　and　rheological　indicators.　Notably,　the　high-elastic　modified　asphalt　showed　the　greatest　aging　resistance　at　all　aging　states　as　a　result　of　its　weak　dual　effects　and　most　uniform　polymer　molecular　distribution.