People　commonly　use　bluffing　as　a　strategy　to　manipulate　other　people＇s　beliefs　about　them　for　gain.　Although　bluffing　is　an　important　part　of　successful　strategic　thinking,　the　inter-brain　mechanisms　underlying　bluffing　remain　unclear.　Here,　we　employed　a　functional　near-infrared　spectroscopy　hyperscanning　technique　to　simultaneously　record　the　brain　activity　in　the　right　temporal-parietal　junction　in　32　pairs　of　participants　when　they　played　a　bluffing　game　against　each　other　or　with　computer　opponents　separately.　We　also　manipulated　the　penalty　for　bluffing　(high　vs　low).　Under　the　condition　of　high　relative　to　low　penalty,　results　showed　a　higher　bluffing　rate　and　a　higher　calling　rate　in　human-to-human　as　compared　to　human-to-computer　pairing.　At　the　neural　level,　high　relative　to　low　penalty　condition　increased　the　interpersonal　brain　synchronization　(IBS)　in　the　right　angular　gyrus　(rAG)　during　human-to-human　as　compared　to　human-to-computer　interaction.　Importantly,　bluffing　relative　to　non-bluffing,　under　the　high　penalty　and　human-to-human　condition,　resulted　in　an　increase　in　response　time　and　enhanced　IBS　in　the　rAG.　Participants　who　bluffed　more　frequently　also　elicited　stronger　IBS.　Our　findings　support　the　view　that　regions　associated　with　mentalizing　become　synchronized　during　bluffing　games,　especially　under　the　high　penalty　and　human-to-human　condition.