According to a new study of Silurian-Devonian conodont biostratigraphy and conodont fauna of Fengyi, Binchuan and Xiangyun area along the E shore of Erhai Lake, Dali, the authors think that the lithostratigraphic unit in traditional division must belong to Kanglang Formation, Qingshan Formation, Lianhuaqu Formation, Changyucun Formation, which must be from later period of Early Silurian to Early Carboniferous in the geological time. And the boundary between Devonian and Silurian must be fixed at the upper part of Qingshan Formation.