The　influence　of　roasting　on　tea　bitterness　remains　unclear.　With　Wuyi　Rock　tea　(WRT)　as　an　example,　this　study　investigated　the　impact　of　roasting　on　WRT＇s　bitterness,　utilizing　an　integrated　approach　involving　sensory　evaluation,　bitter　compound　profiling,　and　cell-based　calcium　imaging.　Sensory　analysis　revealed　that　roasting　effectively　reduced　the　perceived　bitterness　of　WRT.　This　reduction　was　supported　by　decreases　in　various　bitter　compounds,　including　19　flavanols,　11　flavonols,　12　phenolic　acids,　2　purine　alkaloids,　and　9　bitter　amino　acids,　which　diminished　by　16%,　26%,　19%,　2%,　and　70%,　respectively.　Furthermore,　we　established　two　heterogeneous　bitter　receptor　expression　systems:　TAS2R39/G　alpha　15-HEK293T　and　TAS2R14/G　alpha　15-HEK293T　cell　lines.　These　systems　quantitatively　confirmed　the　reduction　in　bitterness,　demonstrating　51%　and　62%　decreases　in　intracellular　calcium　mobilization　within　the　transfected　cells,　respectively.　These　findings　provide　compelling　evidence　for　the　bitterness-ameliorating　effect　of　roasting,　expanding　our　knowledge　of　the　role　of　roasting　in　shaping　the　flavor　of　tea.