Adjacent　grains　slip　transfer　is　an　important　mechanism　for　metal　adaptation　to　incompatibilities　in　intergranular　deformation.　Thus,　this　paper　investigates　slip　transmission　at　grain　boundaries　(GBs)　and　annealed　twin　boundaries　(TBs)　in　Inconel　718　(IN718)　alloy　using　in-situ　tensile　test　at　650　°C　by　integrating　slip　trace　analysis　and　the　crystal　plasticity　finite　element　method　(CPFEM).　Results　show　that　the　mαβ　criterion,　based　on　the　match　of　intersection　lines　between　slip　planes　to　GB　planes　and　slip　directions,　is　more　reasonable　in　predicting　induced　activated　slip　systems　than　Luster-Morris　mαβ′　criterion.　In　addition,　slip　transfer　tended　to　occur　at　mαβ′＞0.83　and　Δb(1/b)＜0.44　or　mαβ＞0.82　and　Δb(1/b)＜0.46　for　general　GBs;　when　mαβ′＞0.92　or　mαβ＞0.93,　continuous　slip　transfer　is　a　crucial　mechanism　to　coordinate　strain　and　reduce　stress　concentration.　Furthermore,　the　acceptable　criteria　for　slip　transfer　at　TBs　are　θ≈0　and　Δb(1/b)＜0.6　by　experimental　and　computational　results.　This　study　deepens　the　understanding　of　the　adjacent　grains　slip　transfer　behavior　of　IN718　and　also　provides　a　new　strategy　to　study　the　deformation　behavior　of　Nickel-based　superalloys.　©　2023　Elsevier　Ltd