Due　to　its　significance　in　oil　recovery　and　droplet　microfluidics,　breakup　of　spherical　droplets　in　a　constriction　(i.e.,　snap-off)　is　extensively　studied.　However,　rectangular　channels　with　large　aspect　ratios　are　commonly　used　in　real　applications,　in　which　droplets　usually　present　pancake　shape.　Since　capillary　pressures　governing　droplet＇s　snap-off　depend　strongly　on　droplet　shape,　we　hypothesize　that　pancake　droplets　may　exhibit　different　snap-off　behaviors　from　spherical　droplets.　Via　microfluidic　experiments,　we　demonstrate　that　pancake　droplets　indeed　present　new　snap-off　behaviors　in　three　aspects:　(1)　they　snap　off　at　high　capillary　numbers;　(2)　the　interface　breaks　up　at　the　rear　meniscus　instead　of　the　front　one;　(3)　the　size　of　daughter　droplets　is　dependent　of　mother　droplet　size　instead　of　independent　for　spherical　droplets.　Besides,　we　reveal　the　underlying　mechanism,　i.e.,　pancake　droplets　show　much　lower　velocity　in　the　constriction　than　spherical　droplets,　via　analyzing　capillary　pressures　at　the　droplet＇s　two　ends.　©　2020　Elsevier　Ltd