This　study　investigated　a　novel　hypothesis　on　the　influences　of　residual　or　pre-dislocation　structures　on　creep　life　of　Ni-based　single　crystal　superalloys.　Different　types　of　anisotropic　dislocation　structures　were　created　by　pre-straining　the　samples　at　a　relatively　low　temperature　under　different　constant　bias　load　conditions.　After　such　pre-straining　treatment,　the　samples　were　subjected　to　creep　testing　at　higher　temperatures　under　uniaxial　tension.　It　was　found　that　the　pre-straining　treatment　was　effective　in　creating　different　anisotropic　dislocation　structures　without　affecting　the　gamma＇　phase　cuboid　morphology　and　that　the　samples　containing　different　anisotropic　dislocation　structures　have　all　significantly　reduced　creep　lives.　The　difference　in　the　anisotropy　of　the　dislocation　structures　has　little　influence　on　the　reduction　of　the　creep　life　or　the　rafting　morphology　of　the　gamma＇　phase　cuboids.　By　using　a　Re-free　alloy,　the　influence　of　the　TCP　phase　precipitation　on　creep　life　is　also　clarified.　These　observations　suggest　that　interruption　to　high　temperature　straining　is　the　main　contributor　to　the　reduced　creep　lives.　This　finding　raises　a　serious　concern　on　the　validity,　or　reliability,　of　creep　life　assessment　based　on　continuous　laboratory　creep　tests　for　real　life　applications,　where　the　services　are　almost　always　interrupted　into　intermittent　sessions.　(C)　2019　The　Authors.　Published　by　Elsevier　Ltd.