This　work　investigates　the　effect　of　microstructural　degradation　on　the　overtemperature　rupture　performance　in　Ru-containing　Ni-based　single　crystal　superalloys.　Unlike　the　initial　samples,　the　rupture　lives　in　the　degraded　sample　are　largely　lost,　and　adding　Ru　in　the　degraded　sample　increases　the　rupture　life　at　1120　degrees　C/100　MPa　and　1180　degrees　C/100　MPa.　Based　on　the　difference　in　the　microstructure　and　microstructural　evolution　in　the　initial　and　degraded　samples.　Their　influence　on　the　rupture　performance　can　be　derived.　The　enlarged　width　of　the　gamma　matrix　is　the　major　reason　for　the　reduction　of　the　rupture　life　and　increase　in　the　strain　for　the　degraded　sample　compared　to　the　initial　samples.　The　existence　of　the　dislocation　network　and　the　inhibition　of　the　precipitation　of　the　TCP　phase　are　the　major　reasons　for　the　lower　rupture　life　reduction　in　the　5Ru　degraded　sample　than　in　the　3Ru　degraded　sample.　The　mobility　of　the　dislocation　increases　with　the　temperature,　weakening　the　benefit　effect　caused　by　Ru.