Web　services　choreography　describes　the　global　model　of　service　interactions　among　a　set　of　participants.　In　order　to　achieve　a　common　business　goal,　the　protocols　for　interactions　must　be　correct.　Experiences　show　that　it　is　difficult　to　check　choreography　manually,　even　it　is　not　very　complex.　A　scenario　describes　a　sequence　of　interactions　among　the　collaborative　participants,　that　is　useful　for　judging　if　a　choreography　satisfies　the　intended　business　requirements.　However,　building　the　scenarios　for　a　choreography　is　not　easy　even　if　with　a　supporting　tool,　such　as　Pi4SOA.　In　this　paper,　we　propose　an　approach,　and　a　set　of　algorithms,　for　generating　the　scenarios　of　a　choreography　automatically.　For　the　fundamental　study,　a　small　choreography　language　CDL　capturing　the　core　features　of　Web　services　choreography　description　language　WS-CDL　is　developed,　with　its　formal　syntax　and　trace　semantics.　The　scenarios　are　defined　basing　on　the　choreography　model,　and　the　algorithms　for　generating　scenarios　from　CDL　is　presented.　We　use　a　purchase　order　example　to　show　how　service　choreography　can　be　specified　in　CDL,　and　how　the　scenarios　are　generated　and　used　to　check　the　choreography.　A　prototype　tool　has　been　developed　on　Pi4SOA　which　shows　the　approach　is　both　viable　and　effective.　©　2011　IEEE.